3
3.0
Jun 29, 2018
06/18
by
V. V. Val'kov; D. M. Dzebisashvili; A. F. Barabanov
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eye 3
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It is shown that the spin-fermion model found to be an effective low-energy implementation of the three-band Emery model after Wannier transformation of $p_x$- and $p_y$-orbitals in the oxygen ions subsystem is reduced to the generalized Kondo lattice model. Its essential feature is the presence of spin-correlated hoppings of the current carriers between distant cells. Numerical calculations of the spin-polaron spectrum demonstrate the important role of the distant hoppings.
Topics: Superconductivity, Condensed Matter, Strongly Correlated Electrons
Source: http://arxiv.org/abs/1606.04727
4
4.0
Jun 30, 2018
06/18
by
D. Ferraro; M. Carrega; A. Braggio; M. Sassetti
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We investigate the finite frequency (f.f.) noise properties of edge states in the quantum Hall regime. We consider the measurement scheme of a resonant detector coupled to a quantum point contact in the weak-backscattering limit. A detailed analysis of the difference between the "measured" noise, due to the presence of the resonant detector, and the symmetrized f.f. noise is presented. We discuss both the Laughlin and Jain sequences, studying the tunnelling excitations in these...
Topics: Quantum Gases, Mesoscale and Nanoscale Physics, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1402.6488
2
2.0
Jun 30, 2018
06/18
by
Qiang Zhang; Wei Tian; Spencer G. Peterson; Kevin W. Dennis; David Vaknin
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eye 2
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Structure and magnetic properties of high-quality polycrystlline CeMnAsO, a parent compound of the "1111"-type oxypnictides, have been investigated using neutron powder diffraction and magnetization measurements. We find that CeMnAsO undergoes a C-type antiferromagnetic order with Mn$^{2+}$ ($S=5/2$) moments pointing along the \textit{c}-axis below a relatively high N\'{e}el temperature of $T_{\rm N} = 345$ K. Below $T_{\rm SR} = 35$ K, two instantaneous transitions occur where the Mn...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1411.3380
2
2.0
Jun 30, 2018
06/18
by
Mohammad Alidoust; Klaus Halterman
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eye 2
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Using the Keldysh-Usadel formalism, we theoretically study the $0$-$\pi$ transition profiles and current-phase relations of magnetic $SFSFS$ and $SFSFFS$ Josephson nanojunctions in the diffusive regime. By allowing the magnetizations of the ferromagnetic layers to take arbitrary orientations, the strength and direction of the charge supercurrent flowing through the ferromagnetic regions can be controlled via the magnetization rotation in one of the ferromagnetic layers. Depending on the...
Topics: Quantum Physics, Superconductivity, Mesoscale and Nanoscale Physics, Strongly Correlated Electrons,...
Source: http://arxiv.org/abs/1405.0012
3
3.0
Jun 30, 2018
06/18
by
Ilya Eremin; Johannes Knolle; Rafael M. Fernandes; Jörg Schmalian; Andrey V. Chubukov
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The recent discovery of superconductivity in the iron-based layered pnictides with T_c ranging between 26 and 56K generated enormous interest in the physics of these materials. Here, we review some of the peculiarities of the antiferromagnetic order in the iron pnictides, including the selection of the stripe magnetic order and the formation of the Ising-nematic state in the unfolded BZ within an itinerant description. In addition we analyze the properties of the quasiparticle interference...
Topics: Superconductivity, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1402.7206
2
2.0
Jun 30, 2018
06/18
by
S. Singh; J. T. Haraldsen; J. Xiong; E. M. Choi; P. Lu; D. Yi; X. -D. Wen; J. Liu; H. Wang; Z. Bi; P. Yu; M. R. Fitzsimmons; J. L. MacManus-Driscoll; R. Ramesh; A. V. Balatsky; Jian-Xin Zhu; Q. X. Jia
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eye 2
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Using polarized neutron reflectometry (PNR), we observe an induced magnetization of 75$\pm$ 25 kA/m at 10 K in a La$_{0.7}$Sr$_{0.3}$MnO$_3$ (LSMO)/BiFeO$_3$ superlattice extending from the interface through several atomic layers of the BiFeO$_3$ (BFO). The induced magnetization in BFO is explained by density functional theory, where the size of bandgap of BFO plays an important role. Considering a classical exchange field between the LSMO and BFO layers, we further show that magnetization is...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1407.0723
3
3.0
Jun 30, 2018
06/18
by
Andrea Allais; Johannes Bauer; Subir Sachdev
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eye 3
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We review the transformation of bond order waves with non-trivial form factors under time-reversal and point group symmetry. Zeyher (arXiv:1406.6846) argues that certain d-form factor states must be "flux states", but this does not apply to the form factors as defined by us (arXiv:1402.4807). The latter definitions were used in the experimental detection (arXiv:1402.5415, arXiv:1404.0362).
Topics: Superconductivity, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1407.3281
3
3.0
Jun 30, 2018
06/18
by
B. Barbiellini
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eye 3
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Occupation numbers of natural orbitals capture the physics of strong electron correlations in momentum space. A Natural Orbital Density Functional Theory based on the antisymmetrized geminal product provides these occupation numbers and the corresponding electron momentum density. A practical implementation of this theory approximates the natural orbitals by the Kohn-Sham orbitals and uses a mean-field approach to estimate pairing amplitudes leading to corrections for the independent particle...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1403.0004
4
4.0
Jun 30, 2018
06/18
by
J. Kaczmarczyk; J. Bünemann; J. Spałek
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eye 4
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A systematic diagrammatic expansion for Gutzwiller-wave functions (DE-GWF) proposed very recently is used for the description of superconducting (SC) ground state in the two-dimensional square-lattice $t$-$J$ model with the hopping electron amplitudes $t$ (and $t'$) between nearest (and next-nearest) neighbors. On the example of the SC state analysis we provide a detailed comparison of the method results with other approaches. Namely: (i) the truncated DE-GWF method reproduces the variational...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1401.6792
16
16
Jun 30, 2018
06/18
by
Kush Saha; Ion Garate
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eye 16
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We develop an approximate theory of phonon-induced topological insulation in Dirac materials. In the weak coupling regime, long wavelength phonons may favor topological phases in Dirac insulators with direct and narrow bandgaps. This phenomenon originates from electron-phonon matrix elements, which change qualitatively under a band inversion. A similar mechanism applies to weak Coulomb interactions and spin-independent disorder; however, the influence of these on band topology is largely...
Topics: Mesoscale and Nanoscale Physics, Strongly Correlated Electrons, Materials Science, Condensed Matter
Source: http://arxiv.org/abs/1403.3880
4
4.0
Jun 30, 2018
06/18
by
Christoph Heil; Lilia Boeri; Heinrich Sormann; Wolfgang von der Linden; Markus Aichhorn
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We perform electronic structure calculations for the recently synthesized iron-based superconductor LiFeO$_2$Fe$_2$Se$_2$. In contrast to other iron-based superconductors, this material comprises two different iron atoms in 3$d^5$ and 3$d^6$ configurations. In band theory, both contribute to the low-energy electronic structure. Spin-polarized density functional theory calculations predict an antiferromagnetic metallic ground state with different moments on the two Fe sites. However, several...
Topics: Superconductivity, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1408.0960
3
3.0
Jun 30, 2018
06/18
by
S Jang; B D White; P -C Ho; N Kanchanavatee; M Janoscheck; J J Hamlin; M B Maple
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A crossover from a non-Fermi liquid to a Fermi liquid phase in Yb$_2$Ni$_{12}$P$_7$ is observed by analyzing electrical resistivity $\rho(T)$, magnetic susceptibility $\chi(T)$, specific heat $C(T)$, and thermoelectric power $S(T)$ measurements. The electronic contribution to specific heat, $C_{e}(T)$, behaves as $C_{e}(T)/T \sim -\ln(T)$ for 5 K $ < T $ 4 K. A crossover between Fermi-liquid and non-Fermi liquid behavior suggests that Yb$_2$Ni$_{12}$P$_7$ is in close proximity to a quantum...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1409.2066
4
4.0
Jun 30, 2018
06/18
by
E. Svanidze; Jiakui K. Wang; T. Besara; L. Liu; Q. Huang; T. Siegrist; B. Frandsen; J. W. Lynn; Andriy H. Nevidomskyy; Monika Barbara Gamża; M. C. Aronson; Y. J. Uemura; E. Morosan
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eye 4
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Itinerant and local moment magnetism have substantively different origins, and require distinct theoretical treatment. A unified theory of magnetism has long been sought after, and remains elusive, mainly due to the limited number of known itinerant magnetic systems. In the case of the two such examples discovered several decades ago, the itinerant ferromagnets ZrZn_2 and Sc_3In, the understanding of their magnetic ground states draws on the existence of 3d electrons subject to strong spin...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1409.0811
11
11
Jun 26, 2018
06/18
by
Frédéric Piéchon; Yoshikazu Suzumura; Takao Morinari
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eye 11
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Dirac electrons with a zero-gap state (ZGS) in organic conductor $\alpha$-(BEDT-TTF)$_2$I$_3$ result from a fine tuning of the seven nearest neighbors transfer integrals ($a_1, a_2, a_3, b_1, b_2, b_3, b_4$) between the four molecules of the unit cell. In this work we show that for given moduli $|a_1|,...|b_4|$, the possibility of having Dirac electron with a ZGS at $3/4$ (or $1/4$) filling strongly depends on the specific configurations of signs of the seven transfer integral. More precisely...
Topics: Strongly Correlated Electrons, Other Condensed Matter, Condensed Matter
Source: http://arxiv.org/abs/1502.01167
7
7.0
Jun 26, 2018
06/18
by
Li Yang; Liming Guan; Han Pu
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eye 7
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Under the second-order degenerate perturbation theory, we show that the physics of $N$ particles with arbitrary spin confined in a one dimensional trap in the strongly interacting regime can be described by super-exchange interaction. An effective spin-chain Hamiltonian (non-translational-invariant Sutherland model) can be constructed from this procedure. For spin-1/2 particles, this model reduces to the non-translational-invariant Heisenberg model, where a transition between Heisenberg...
Topics: Strongly Correlated Electrons, Quantum Gases, Quantum Physics, Condensed Matter
Source: http://arxiv.org/abs/1502.01706
8
8.0
Jun 26, 2018
06/18
by
W. T. Jin; Wei Li; Y. Su; S. Nandi; Y. Xiao; W. H. Jiao; M. Meven; A. P. Sazonov; E. Feng; Yan Chen; C. S. Ting; G. H. Cao; Th. Brückel
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The magnetic order of the localized Eu$^{2+}$ spins in optimally-doped Eu(Fe$_{1-x}$Ir$_{x}$)$_{2}$As$_{2}$ ($\mathit{x}$ = 0.12) with superconducting transition temperature $\mathit{T_{SC}}$ = 22 K was investigated by single-crystal neutron diffraction. The Eu$^{2+}$ moments were found to be ferromagnetically aligned along the $\mathit{c}$-direction with an ordered moment of 7.0(1) $\mu_{B}$ well below the magnetic phase transition temperature $\mathit{T_{C}}$ = 17 K. No evidence of the...
Topics: Superconductivity, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1502.01921
11
11
Jun 26, 2018
06/18
by
Koji Ikeura; Hideaki Sakai; Mohammad Saeed Bahramy; Shintaro Ishiwata
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eye 11
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MoTe2 is a rare transition-metal ditelluride having two kinds of layered polytypes, hexagonal structure with trigonal prismatic Mo coordination and monoclinic structure with octahedral Mo coordination. The monoclinic distortion in the latter is caused by anisotropic metal-metal bonding. In this work, we have examined the Nb doping effect on both polytypes of MoTe2 and clarified a structural phase diagram for Mo1-xNbxTe2 containing four kinds of polytypes. A rhombohedral polytype crystallizing...
Topics: Strongly Correlated Electrons, Superconductivity, Condensed Matter, Materials Science
Source: http://arxiv.org/abs/1502.05634
11
11
Jun 27, 2018
06/18
by
M. Ciomaga Hatnean; M. R. Lees; O. A. Petrenko; D. S. Keeble; G. Balakrishnan; M. J. Gutmann; V. V. Klekovkina; B. Z. Malkin
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eye 11
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We report structural and magnetic properties studies of large high quality single-crystals of the frustrated magnet, Nd$_2$Zr$_2$O$_7$. Powder x-ray diffraction analysis confirms that Nd$_2$Zr$_2$O$_7$ adopts the pyrochlore structure. Room-temperature x-ray diffraction and time-of-flight neutron scattering experiments show that the crystals are stoichiometric in composition with no measurable site disorder. The temperature dependence of the magnetic susceptibility shows no magnetic ordering at...
Topics: Strongly Correlated Electrons, Condensed Matter, Materials Science
Source: http://arxiv.org/abs/1505.02931
12
12
Jun 28, 2018
06/18
by
G. Montambaux; D. Jérome
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eye 12
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We review the physics of magnetic quantum oscillations in quasi-one dimensional conductors with an open Fermi surface, in the presence of modulated order. We emphasize the difference between situations where a modulation couples states on the same side of the Fermi surface and a modulation couples states on opposite sides of the Fermi surface. We also consider cases where several modulations coexist, which may lead to a complex reorganization of the Fermi surface. The interplay between nesting...
Topics: Strongly Correlated Electrons, Condensed Matter, Materials Science
Source: http://arxiv.org/abs/1507.00037
9
9.0
Jun 27, 2018
06/18
by
Y. Lu; E. Benckiser; B. Keimer
texts
eye 9
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We show that the experimental evidence presented in this paper is insufficient to support its conclusions.
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1506.02787
12
12
Jun 28, 2018
06/18
by
Dung-Hai Lee
texts
eye 12
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This note reviews some of the recent progresses in the study of high temperature superconductivity in the interface between a single unit cell FeSe and SrTiO$_3$. It offers the author's personal view of why $T_c$ is high and how to further increase it.
Topics: Superconductivity, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1508.02461
11
11
Jun 28, 2018
06/18
by
W. C. Haxton; Daniel J. Haxton
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eye 11
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A set of scalar operators are employed to generate explicit representations of both hierarchy states (e.g., the series of fillings 1/3, 2/5, 3/7, ... ) and their conjugates (fillings 1, 2/3, 3/5, ...) as non-interacting quasi-electrons filling fine-structure sub-shells within the FLL. This yields, for planar and spherical geometries, a quasi-electron representation of the incompressible FLL state of filling p/(2p +1) in a magnetic field of strength B that is algebraically identical to the IQHE...
Topics: Physics, Chemical Physics, Strongly Correlated Electrons, Condensed Matter, Nuclear Theory
Source: http://arxiv.org/abs/1508.04184
5
5.0
Jun 28, 2018
06/18
by
Chao-Ming Jian; Isaac H. Kim; Xiao-Liang Qi
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eye 5
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Ordered phases in Landau paradigm can be diagnosed by a local order parameter, whereas topologically ordered phases cannot be detected in such a way. In this paper, we propose long-range mutual information(LRMI) as a unified diagnostic for both conventional long-range order and topological order. Using the LRMI, we characterize orders in $n+1$D gapped systems as $m$-membrane condensates with $ 0 \leq m \leq n-1$. The familiar conventional order and 2+1D topological orders are respectively...
Topics: Quantum Physics, Strongly Correlated Electrons, Condensed Matter, High Energy Physics - Theory
Source: http://arxiv.org/abs/1508.07006
7
7.0
Jun 28, 2018
06/18
by
Johan Hellsvik; Johan H. Mentink; José Lorenzana
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eye 7
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The multiferroic compound CuO exhibits low temperature magnetic properties similar to antiferromagnetic iron oxides, while the electronic properties have much more in common with the high $T_c$ cuprate superconductors. This suggests novel possibilities for the ultrafast optical excitation of magnetism. On the basis on atomistic spin dynamics simulations, we study the effect of phonon-assisted multimagnon absorption and photodoping on the spin dynamics in the vicinity of the first-order phase...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1509.03202
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17
Jun 28, 2018
06/18
by
J. P. Sun; K. Matsuura; G. Z. Ye; Y. Mizukami; M. Shimozawa; K. Matsubayashi; M. Yamashita; T. Watashige; S. Kasahara; Y. Matsuda; J. -Q. Yan; B. C. Sales; Y. Uwatoko; J. -G. Cheng; T. Shibauchi
texts
eye 17
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The coexistence and competition between superconductivity and electronic orders, such as spin or charge density waves, have been a central issue in high transition-temperature (${T_{\rm c}}$) superconductors. Unlike other iron-based superconductors, FeSe exhibits nematic ordering without magnetism whose relationship with its superconductivity remains unclear. More importantly, a pressure-induced fourfold increase of ${T_{\rm c}}$ has been reported, which poses a profound mystery. Here we report...
Topics: Superconductivity, Materials Science, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1512.06951
4
4.0
Jun 29, 2018
06/18
by
Lan-ying Wei; Yi-feng Yang
texts
eye 4
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We examine the doping effects in the two-dimensional periodic Anderson model using the determinant Quantum Monte Carlo (DQMC) method. We observe bound states around the Kondo hole site and find that the heavy electron states are destroyed at the nearest-neighbor sites. Our results show no clear sign of hybridization oscillation predicted in previous mean-field calculations. We further study the electron transport with increasing doping and as a function of temperature and obtain a critical...
Topics: Condensed Matter, Strongly Correlated Electrons
Source: http://arxiv.org/abs/1610.03160
4
4.0
Jun 30, 2018
06/18
by
Jing Chen; Song Cheng; Haidong Xie; Lei Wang; Tao Xiang
texts
eye 4
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Restricted Boltzmann machine (RBM) is one of the fundamental building blocks of deep learning. RBM finds wide applications in dimensional reduction, feature extraction, and recommender systems via modeling the probability distributions of a variety of input data including natural images, speech signals, and customer ratings, etc. We build a bridge between RBM and tensor network states (TNS) widely used in quantum many-body physics research. We devise efficient algorithms to translate an RBM...
Topics: Strongly Correlated Electrons, Machine Learning, Condensed Matter, Quantum Physics, Statistics
Source: http://arxiv.org/abs/1701.04831
6
6.0
Jun 30, 2018
06/18
by
M Ruminy; S Chi; S Calder; T Fennell
texts
eye 6
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To understand emergent magnetic monopole dynamics in the spin ices Ho$_2$Ti$_2$O$_7$ and Dy$_2$Ti$_2$O$_7$, it is necessary to investigate the mechanisms by which spins flip in these materials. Presently there are thought to be two processes: quantum tunneling at low and intermediate temperatures and thermally activated at high temperatures. We identify possible couplings between crystal field and optical phonon excitations and construct a strictly constrained model of phonon-mediated spin...
Topics: Strongly Correlated Electrons, Condensed Matter, Other Condensed Matter
Source: http://arxiv.org/abs/1702.04612
3
3.0
Jun 30, 2018
06/18
by
Zhenzhong Shi; Peter M. Marley; Katie Farley; Sarbajit Banerjee; G. Sambandamurthy
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eye 3
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Electrical transport and broadband resistance noise measurements in an ultra low frequency window (30 mHz - 8 Hz) are carried out in single nanoribbon devices of charge density wave (CDW) conductor NbSe$_{3}$. In the temperature and electric field range where the CDW is expected to be completed pinned by residual impurities, a hitherto unseen non-monotonic behavior in the noise magnitude vs. electric field is observed. This behavior can be attributed to the proliferation of thermally activated...
Topics: Mesoscale and Nanoscale Physics, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1410.8428
4
4.0
Jun 28, 2018
06/18
by
S. A. Grigera; R. Borzi; D. G. Slobinsky; A. S. Gibbs; R. Higashinaka; Y. Maeno; T. S. Grigera
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eye 4
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Dy$_2$Ti$_2$O$_7$ is at present the cleanest example of a spin-ice material. Previous theoretical and experimental work on the first-order transition between the kagome-ice and the fully polarized state has been taken as a validation for the dipolar spin-ice model. Here we investigate in further depth this phase transition using ac-susceptibility and dc-magnetization, and compare this results with Monte-Carlo simulations and previous magnetization and specific heat measurements. We find...
Topics: Statistical Mechanics, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1510.05962
8
8.0
Jun 29, 2018
06/18
by
B. Fak; S. Bieri; E. Canevet; L. Messio; C. Payen; M. Viaud; C. Guillot-Deudon; C. Darie; J. Ollivier; P. Mendels
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eye 8
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Inelastic neutron scattering is used to study the low-energy magnetic excitations in the spin-1 triangular lattice of the 6H-B phase of Ba$_3$NiSb$_2$O$_9$. We study two powder samples: Ba$_3$NiSb$_2$O$_9$ synthesized under high pressure and Ba$_{2.5}$Sr$_{0.5}$NiSb$_2$O$_9$ in which chemical pressure stabilizes the 6H-B structure. The measured excitation spectra show broad gapless and nondispersive continua at characteristic wave vectors. Our data rules out most theoretical scenarios that have...
Topics: Condensed Matter, Strongly Correlated Electrons
Source: http://arxiv.org/abs/1610.03753
4
4.0
Jun 27, 2018
06/18
by
Imam Makhfudz; Pierre Pujol
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eye 4
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We propose a novel mechanism for the protection against spin gapped states in doped antiferromagnets. It requires the presence of a Chern-Simons term that can be generated by a coupling between spin and an insulator. We first demonstrate that in the presence of this term the vortex loop excitations of the spin sector behave as anyons with fractional statistics. To generate such term, the fermions should have massive Dirac spectrum coupled to the emergent spin field of the spin sector. The Dirac...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1505.02762
4
4.0
Jun 29, 2018
06/18
by
Andrea Zen; Sandro Sorella; Michael J. Gillan; Angelos Michaelides; Dario Alfè
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eye 4
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Diffusion Monte Carlo (DMC) simulations for fermions are becoming the standard to provide high quality reference data in systems that are too large to be investigated via quantum chemical approaches. DMC with the fixed-node approximation relies on modifications of the Green function to avoid singularities near the nodal surface of the trial wavefunction. We show that these modifications affect the DMC energies in a way that is not size-consistent, resulting in large time-step errors. Building...
Topics: Quantum Physics, Computational Physics, Strongly Correlated Electrons, Condensed Matter, Physics,...
Source: http://arxiv.org/abs/1605.08706
3
3.0
Jun 30, 2018
06/18
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V. Murg; F. Verstraete; R. Schneider; P. R. Nagy; O. Legeza
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eye 3
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We present a tree-tensor-network-state (TTNS) method study of the ionic-neutral curve crossing of LiF. For this ansatz, the long-range correlation deviates from the mean-field value polynomially with distance, thus for quantum chemical applications the computational cost could be significantly smaller than that of previous attempts using the density matrix renormalization group (DMRG) method. Optimization of the tensor network topology and localization of the avoided crossing are discussed in...
Topics: Physics, Chemical Physics, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1403.0981
3
3.0
Jun 29, 2018
06/18
by
Arbel Haim; Konrad Wölms; Erez Berg; Yuval Oreg; Karsten Flensberg
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eye 3
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We study one-dimensional topological superconductivity in the presence of time-reversal symmetry. This phase is characterized by having a bulk gap, while supporting a Kramers' pair of zero-energy Majorana bound states at each of its ends. We present a general simple model which is driven into this topological phase in the presence of repulsive electron-electron interactions. We further propose two experimental setups and show that they realize this model at low energies. The first setup is a...
Topics: Mesoscale and Nanoscale Physics, Superconductivity, Condensed Matter, Strongly Correlated Electrons
Source: http://arxiv.org/abs/1605.09385
3
3.0
Jun 30, 2018
06/18
by
O. Cyr-Choinière; S. Badoux; G. Grissonnanche; B. Michon; S. A. A. Afshar; S. Fortier; D. LeBoeuf; D. Graf; J. Day; D. A. Bonn; W. N. Hardy; R. Liang; N. Doiron-Leyraud; Louis Taillefer
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eye 3
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The Seebeck coefficient $S$ of the cuprate YBa$_{2}$Cu$_{3}$O$_{y}$ was measured in magnetic fields large enough to suppress superconductivity, at hole dopings $p = 0.11$ and $p = 0.12$, for heat currents along the $a$ and $b$ directions of the orthorhombic crystal structure. For both directions, $S/T$ decreases and becomes negative at low temperature, a signature that the Fermi surface undergoes a reconstruction due to broken translational symmetry. Above a clear threshold field, a strong new...
Topics: Strongly Correlated Electrons, Condensed Matter, Superconductivity
Source: http://arxiv.org/abs/1704.03829
7
7.0
Jun 28, 2018
06/18
by
Miguel Jorge Bernabe Ferreira; Pramod Padmanabhan; Paulo Teotonio-Sobrinho
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eye 7
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The global $e$-$m$ exchange symmetry of the toric code is realized locally through an exactly solvable Hamiltonian on a two dimensional lattice which has no lattice dislocations and their associated defect line. The Hamiltonian is still changed locally in selected sites where we wish to realize this anyon symmetry. We refer to these selected sites as defect sites in analogy with the usual lattice defects. The operators on the defect sites condense dyons of the toric code and are shown to...
Topics: Strongly Correlated Electrons, Condensed Matter, High Energy Physics - Theory
Source: http://arxiv.org/abs/1508.01399
5
5.0
Jun 27, 2018
06/18
by
Ho N. Phien; Johann A. Bengua; Hoang D. Tuan; Philippe Corboz; Roman Orus
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eye 5
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The infinite Projected Entangled Pair States (iPEPS) algorithm [J. Jordan et al, PRL 101, 250602 (2008)] has become a useful tool in the calculation of ground state properties of 2d quantum lattice systems in the thermodynamic limit. Despite its many successful implementations, the method has some limitations in its present formulation which hinder its application to some highly-entangled systems. The purpose of this paper is to unravel some of these issues, in turn enhancing the stability and...
Topics: Condensed Matter, Quantum Physics, Strongly Correlated Electrons, High Energy Physics - Lattice
Source: http://arxiv.org/abs/1503.05345
7
7.0
Jun 27, 2018
06/18
by
Armin Rahmani; Xiaoyu Zhu; Marcel Franz; Ian Affleck
texts
eye 7
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The Hubbard chain and spinless fermion chain are paradigms of strongly correlated systems, very well understood using Bethe ansatz, Density Matrix Renormalization Group (DMRG) and field theory/renormalization group (RG) methods. They have been applied to one-dimensional materials and have provided important insights for understanding higher dimensional cases. Recently, a new interacting fermion model has been introduced, with possible applications to topological materials. It has a single...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1505.03966
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4.0
Jun 30, 2018
06/18
by
Jan Heyder; Florian Bauer; Dennis Schimmel; Jan von Delft
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We present a Keldysh-based derivation of a formula, previously obtained by Oguri using the Matsubara formalisum, for the linear conductance through a central, interacting region coupled to non-interacting fermionic leads. Our starting point is the well-known Meir-Wingreen formula for the current, whose derivative w.r.t.\ to the source-drain voltage yields the conductance. We perform this derivative analytically, by exploiting an exact flow equation from the functional renormalization group,...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1704.05751
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7.0
Jun 26, 2018
06/18
by
William Witczak-Krempa
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Quantum critical (QC) phase transitions generally lead to the absence of quasiparticles. The resulting correlated quantum fluid, when thermally excited, displays rich universal dynamics. We establish non-perturbative constraints on the linear-response dynamics of conformal QC systems at finite temperature, in spatial dimensions above one. Specifically, we analyze the large frequency/momentum asymptotics of observables, which we use to derive powerful sum rules and inequalities. The general...
Topics: Condensed Matter, Quantum Gases, Strongly Correlated Electrons, Statistical Mechanics, High Energy...
Source: http://arxiv.org/abs/1501.03495
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7.0
Jun 28, 2018
06/18
by
Enej Ilievski; Jacopo De Nardis; Bram Wouters; Jean-Sebastien Caux; Fabian H. L. Essler; Tomaz Prosen
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In integrable many-particle systems, it is widely believed that the stationary state reached at late times after a quantum quench can be described by a generalized Gibbs ensemble (GGE) constructed from their extensive number of conserved charges. A crucial issue is then to identify a complete set of these charges, enabling the GGE to provide exact steady state predictions. Here we solve this long-standing problem for the case of the spin-1/2 Heisenberg chain by explicitly constructing a GGE...
Topics: Quantum Physics, Statistical Mechanics, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1507.02993
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10.0
Jun 27, 2018
06/18
by
F. M. Gambetta; N. Traverso Ziani; F. Cavaliere; M. Sassetti
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In one-channel, finite-size Luttinger one-dimensional quantum dots, both Friedel oscillations and Wigner correlations induce oscillations in the electron density with the same wavelength, pinned at the same position. Therefore, observing such a property does not provide any hint about the formation of a Wigner molecule when electrons interact strongly and other tools must be employed to assess the formation of such correlated states. We compare here the behavior of three different correlation...
Topics: Condensed Matter, Mesoscale and Nanoscale Physics, Strongly Correlated Electrons
Source: http://arxiv.org/abs/1503.06965
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6.0
Jun 28, 2018
06/18
by
Joseph A. M. Paddison; Andrew B. Cairns; Dmitry D. Khalyavin; Pascal Manuel; Aziz Daoud-Aladine; Georg Ehlers; Oleg A. Petrenko; Jason S. Gardner; H. D. Zhou; Andrew L. Goodwin; J. Ross Stewart
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The frustrated pyrochlore antiferromagnet Gd$_{2}$Ti$_{2}$O$_{7}$ has an unusual partially-ordered magnetic structure at the lowest measurable temperatures. This structure is currently believed to involve four magnetic propagation vectors $\mathbf{k}\in \langle \frac{1}{2} \frac{1}{2} \frac{1}{2} \rangle^*$ in a cubic 4-$\mathbf{k}$ structure, based on analysis of magnetic diffuse-scattering data [J. Phys.: Condens. Matter 16, L321 (2004)]. Here, we present three pieces of evidence against the...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1506.05045
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3.0
Jun 30, 2018
06/18
by
Arijit Haldar; Vijay B. Shenoy
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We study a dual flavor fermion model where each of the flavors form a Sachdev-Ye-Kitaev (SYK) system with arbitrary and possibly distinct $q$-body interactions. The crucial new element is an arbitrary all-to-all $r$-body interaction between the two flavors. At high temperatures the model shows a strange metal phase where both flavors are gapless, similar to the usual single flavor SYK model. Upon reducing temperature, the coupled system undergoes phase transitions to previously unseen phases -...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1703.05111
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10.0
Jun 26, 2018
06/18
by
Fabien Tran; Markus Betzinger; Peter Blaha; Stefan Blügel
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The exact-exchange (EXX) potential, which is obtained by solving the optimized-effective potential (OEP) equation, is compared to various approximate semilocal exchange potentials for a set of selected solids (C, Si, BN, MgO, Cu$_{2}$O, and NiO). This is done in the framework of the linearized augmented plane-wave method, which allows for a very accurate all-electron solution of electronic structure problems in solids. In order to assess the ability of the semilocal potentials to approximate...
Topics: Materials Science, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1501.07105
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7.0
Jun 26, 2018
06/18
by
Christof Gattringer; Thomas Kloiber; Vasily Sazonov
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We derive an exact representation of the massless Schwinger model on the lattice in terms of dual variables which are configurations of loops, dimers and plaquette occupation numbers. When expressed with the dual variables the partition sum has only real and positive terms also when a chemical potential or a topological term are added -- situations where the conventional representation has a complex action problem. The dual representation allows for Monte Carlo simulations without restrictions...
Topics: Strongly Correlated Electrons, High Energy Physics - Lattice, Condensed Matter
Source: http://arxiv.org/abs/1502.05479
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5.0
Jun 28, 2018
06/18
by
G. Prando; G. Profeta; A. Continenza; R. Khasanov; A. Pal; V. P. S. Awana; B. Büchner; S. Sanna
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The direct correspondence between Co band ferromagnetism and structural parameters is investigated in the pnictide oxides $R$CoPO for different rare-earth ions ($R$ = La, Pr, Nd, Sm) by means of muon-spin spectroscopy and {\it ab-initio} calculations, complementing our results published previously [G. Prando {\it et al.}, {\it Phys. Rev. B} {\bf 87}, 064401 (2013)]. Both the transition temperature to the ferromagnetic phase $T_{_{\textrm{C}}}$ and the volume of the crystallographic unit cell...
Topics: Superconductivity, Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1506.06211
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4.0
Jun 28, 2018
06/18
by
Philippe Corboz
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An infinite projected entangled-pair state (iPEPS) is a variational tensor network ansatz for 2D wave functions in the thermodynamic limit where the accuracy can be systematically controlled by the bond dimension $D$. We show that for the doped Hubbard model in the strongly correlated regime ($U/t=8$, $n=0.875$) iPEPS yields lower variational energies than state-of-the-art variational methods in the large 2D limit, which demonstrates the competitiveness of the method. In order to obtain an...
Topics: Strongly Correlated Electrons, Condensed Matter
Source: http://arxiv.org/abs/1508.04003
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7.0
Jun 28, 2018
06/18
by
Yuya Tanizaki; Yoshimasa Hidaka; Tomoya Hayata
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The Lefschetz-thimble approach to path integrals is applied to a one-site model of electrons, i.e., the one-site Hubbard model. Since the one-site Hubbard model shows a non-analytic behavior at the zero temperature and its path integral expression has the sign problem, this toy model is a good testing ground for an idea or a technique to attack the sign problem. Semiclassical analysis using complex saddle points unveils the significance of interference among multiple Lefschetz thimbles to...
Topics: High Energy Physics - Lattice, Strongly Correlated Electrons, Condensed Matter, High Energy Physics...
Source: http://arxiv.org/abs/1509.07146
