The Experts below are selected from a list of 237963 Experts worldwide ranked by ideXlab platform
T Senthil - One of the best experts on this subject based on the ideXlab platform.
-
translationally invariant non fermi Liquid metals with critical fermi surfaces solvable models
Physical Review X, 2018Co-Authors: Debanjan Chowdhury, Yochai Werman, Erez Berg, T SenthilAbstract:Understanding the properties of metals beyond the Fermi Liquid paradigm is one of the central challenges of condensed matter physics. New exactly solvable microscopic models of Non-Fermi Liquid metals offer new insights into many properties of these exotic systems.
-
translationally invariant non fermi Liquid metals with critical fermi surfaces solvable models
arXiv: Strongly Correlated Electrons, 2018Co-Authors: Debanjan Chowdhury, Yochai Werman, Erez Berg, T SenthilAbstract:We construct examples of translationally invariant solvable models of strongly-correlated metals, composed of lattices of Sachdev-Ye-Kitaev dots with identical local interactions. These models display crossovers as a function of temperature into regimes with local quantum criticality and marginal-Fermi Liquid behavior. In the marginal Fermi Liquid regime, the dc resistivity increases linearly with temperature over a broad range of temperatures. By generalizing the form of interactions, we also construct examples of Non-Fermi Liquids with critical Fermi-surfaces. The self energy has a singular frequency dependence, but lacks momentum dependence, reminiscent of a dynamical mean field theory-like behavior but in dimensions $d<\infty$. In the low temperature and strong-coupling limit, a heavy Fermi Liquid is formed. The critical Fermi-surface in the Non-Fermi Liquid regime gives rise to quantum oscillations in the magnetization as a function of an external magnetic field in the absence of quasiparticle excitations. We discuss the implications of these results for local quantum criticality and for fundamental bounds on relaxation rates. Drawing on the lessons from these models, we formulate conjectures on coarse grained descriptions of a class of intermediate scale Non-Fermi Liquid behavior in generic correlated metals.
-
Lattice models for Non-Fermi-Liquid metals
Physical Review B, 2008Co-Authors: Michael Levin, T SenthilAbstract:We present two 2D lattice models with Non-Fermi Liquid metallic phases. We show that the low energy physics of these models is exactly described by a Fermi sea of fractionalized quasiparticles coupled to a fluctuating U(1) gauge field. In the first model, the underlying degrees of freedom are spin 1/2 fermions. This model demonstrates that electrons can in principle give rise to Non-Fermi Liquid metallic phases. In the second model, the underlying degrees of freedom are spinless bosons. This model provides a concrete example of a (Non-Fermi Liquid) Bose metal. With little modification, it also gives an example of a critical U(1) symmetric spin Liquid.
-
On Non-Fermi Liquid quantum critical points in heavy fermion metals
Annals of Physics, 2006Co-Authors: T SenthilAbstract:Abstract Heavy electron metals on the verge of a quantum phase transition to magnetism show a number of unusual Non-Fermi Liquid properties which are poorly understood. This article discusses in a general way various theoretical aspects of this phase transition with an eye toward understanding the Non-Fermi Liquid phenomena. We suggest that the Non-Fermi Liquid quantum critical state may have a sharp Fermi surface with power law quasiparticles but with a volume not set by the usual Luttinger rule. We also discuss the possibility that the electronic structure change associated with the possible Fermi surface reconstruction may diverge at a different time/length scale from that associated with magnetic phenomena.
Chao-ming Jian - One of the best experts on this subject based on the ideXlab platform.
-
Non-Landau Quantum Phase Transitions and nearly-Marginal Non-Fermi Liquid
Journal of Statistical Mechanics: Theory and Experiment, 2020Co-Authors: Hao Geng, Chao-ming JianAbstract:Non-Fermi Liquid and unconventional quantum critical points (QCP) with strong fractionalization are two exceptional phenomena beyond the classic condensed matter doctrines, both of which could occur in strongly interacting quantum many-body systems. This work demonstrates that using a controlled method one can construct a Non-Fermi Liquid within a considerable energy window based on the unique physics of unconventional QCPs. We will focus on the "nearly-marginal Non-Fermi Liquid", defined as a state whose fermion self-energy scales as $\Sigma_f(i \omega) \sim i \mathrm{sgn}(\omega)|\omega|^{\alpha}$ with $\alpha$ close to $1$ in a considerable energy window. The nearly-marginal Non-Fermi Liquid is obtained by coupling an electron fermi surface to unconventional QCPs that are beyond the Landau's paradigm. This mechanism relies on the observation that the anomalous dimension $\eta$ of the order parameter of these unconventional QCPs can be close to $1$, which is significantly larger than conventional Landau phase transitions, for example the Wilson-Fisher fixed points. The fact that $\eta \sim 1$ justifies a perturbative renormalization group calculation proposed earlier. Various candidate QCPs that meet this desired condition are proposed.
-
quantum simulation of the non fermi Liquid state of sachdev ye kitaev model
npj Quantum Information, 2019Co-Authors: Zhihuang Luo, Chao-ming Jian, Yizhuang You, Bei Zeng, Raymond LaflammeAbstract:The Sachdev-Ye-Kitaev (SYK) model incorporates rich physics, ranging from exotic Non-Fermi Liquid states without quasiparticle excitations, to holographic duality and quantum chaos. However, its experimental realization remains a daunting challenge due to various unnatural ingredients of the SYK Hamiltonian such as its strong randomness and fully nonlocal fermion interaction. At present, constructing such a nonlocal Hamiltonian and exploring its dynamics is best through digital quantum simulation, where state-of-the-art techniques can already handle a moderate number of qubits. Here, we demonstrate a first step towards simulation of the SYK model on a nuclear-spin-chain simulator. We observed the fermion paring instability of the Non-Fermi Liquid state and the chaotic-nonchaotic transition at simulated temperatures, as was predicted by previous theories. As the realization of the SYK model in practice, our experiment opens a new avenue towards investigating the key features of Non-Fermi Liquid states, as well as the quantum chaotic systems and the AdS/CFT duality.
Thomas Schäfer - One of the best experts on this subject based on the ideXlab platform.
-
Non-Fermi Liquid Effective Field Theory of Dense QCD Matter
Nuclear Physics, 2007Co-Authors: Thomas SchäferAbstract:We introduce an effective field theory for quasi-particles in dense QCD matter. Unscreened magnetic gluon exchanges lead to Non-Fermi Liquid behavior. Non-Fermi Liquid effects manifest themselves in low energy Green functions that depend on logarithms and fractional powers of energy. We discuss the validity of some standard theorems of Fermi Liquid theory.
-
Non-Fermi Liquid Effective Field Theory of Dense QCD Matter
Nuclear Physics A, 2007Co-Authors: Thomas SchäferAbstract:We review an effective field theory for the Non-Fermi Liquid regime of dense QCD matter. Non-Fermi Liquid effects arise due the presence of unscreened magnetic gluon exchanges. We show that there is a systematic low energy expansion in fractional powers and logarithms of energy. We discuss the validity of some standard theorems of Fermi Liquid theory.Comment: 4 pages; Contribution to the proceedings of the International Conference on Strong & Electroweak Matter 2006, Brookhaven National Laboratory, Upton, NY, May 200
Yong Baek Kim - One of the best experts on this subject based on the ideXlab platform.
-
critical theory of non fermi Liquid fixed point in multipolar kondo problem
Physical Review X, 2020Co-Authors: Adarsh S Patri, Yong Baek KimAbstract:A mathematical analysis reveals the existence of a novel type of Non-Fermi Liquid, an exotic metallic state governed by strong interactions between conduction electrons and a multipolar (ion) impurity.
-
Rise and Fall of Non-Fermi Liquid Fixed Points in Multipolar Kondo Problems
arXiv: Strongly Correlated Electrons, 2020Co-Authors: Daniel Schultz, Adarsh S Patri, Yong Baek KimAbstract:Recently it was shown that the multipolar Kondo problem, wherein a quantum impurity carrying higher-rank multipolar moments interacts with conduction electrons, leads to novel Non-Fermi Liquid states. Because of the multipolar character of the local moments, the form of the interaction with conduction electrons is strongly dependent on the orbital-symmetry of the conduction electrons via crystalline symmetry constraints. This suggests that there may exist a variety of different Non-Fermi Liquid states in generic multipolar Kondo problems depending on the character of conduction electrons. In this work, using renormalization group analysis, we investigate a model where the multipolar local moment is coupled to conduction electrons with two different orbital-symmetry components, namely $p$-wave and $f$-wave symmetries. When each orbital-symmetry component is present alone, Non-Fermi Liquid states with exactly the same thermodynamic singularities appear. When both orbital-symmetry components are allowed, however, a completely different Non-Fermi Liquid state arises via the quantum fluctuations in the mixed scattering channels. This remarkable result suggests that the multipolar Kondo problem presents novel opportunities for the discovery of unexpected Non-Fermi Liquid states.
-
critical theory of non fermi Liquid fixed point in multipolar kondo problem
arXiv: Strongly Correlated Electrons, 2020Co-Authors: Adarsh S Patri, Yong Baek KimAbstract:When the ground state of a localized ion is a non-Kramers doublet, such localized ions may carry multipolar moments. For example, Pr$^{3+}$ ions in a cubic environment would possess quadrupolar and octupolar, but no magnetic dipole, moments. When such multipolar moments are placed in a metallic host, unusual interactions between these local moments and conduction electrons arise, in contrast to the familiar magnetic dipole interactions in the classic Kondo problem. In this work, we consider the interaction between a single quadrupolar-octupolar local moment and conduction electrons with $p$-orbital symmetry as a concrete model for the multipolar Kondo problem. We show that this model can be written most naturally in the spin-orbital entangled basis of conduction electrons. Using this basis, the perturbative renormalization group (RG) fixed points are readily identified. There are two kinds of fixed points, one for the two-channel Kondo and the other for a novel fixed point. We investigate the nature of the novel fixed point non-perturbatively using non-abelian bosonization, current algebra and conformal field theory approaches. It is shown that the novel fixed point leads to a, previously unidentified, Non-Fermi Liquid state with entangled spin and orbital degrees of freedom, which shows resistivity $\rho \sim T^{\Delta}$ and diverging specific heat coefficient $C/T \sim T^{-1 + 2\Delta}$ with $\Delta=1/5$. Our results open up the possibility of myriads of Non-Fermi Liquid states, depending on the choices of multipolar moments and conduction electron orbitals, which would be relevant for many rare-earth metallic systems.
-
emergent non fermi Liquid phenomena in multipolar quantum impurity systems
Physical Review Research, 2020Co-Authors: Adarsh S Patri, Ilia Khait, Yong Baek KimAbstract:In this work, the authors study the interactions between higher-rankmultipolar quantum impurities and conduction electrons in spin-orbitalentangled systems. Using perturbative renormalization grouptechniques, they uncover a number of novel Non-Fermi Liquid groundstates characterized by highly singular scaling behaviors in physicalproperties. The discovered Non-Fermi Liquid states are outside theknown categories of Non-Fermi Liquid states found in the conventionalmulti-channel Kondo problem
-
emergent non fermi Liquid phenomena in multipolar quantum impurity systems
arXiv: Strongly Correlated Electrons, 2019Co-Authors: Adarsh S Patri, Ilia Khait, Yong Baek KimAbstract:Discovery of novel spin-orbital entangled quantum ground states paves an important avenue for controllable quantum materials via unique couplings to the lattice and other external perturbations. In this work, motivated by recent experiments on cubic heavy fermion materials with multipolar local moments, we theoretically investigate strongly-interacting spin-orbital entangled quantum ground states in multipolar quantum impurity systems. Here itinerant electrons are interacting with the local moments carrying quadrupolar and octupolar moments, in contrast to the conventional Kondo problem with dipolar local moment. Using perturbative renormalization group methods, we uncover a number of Non-Fermi Liquid ground states, which are characterized by an absence of well-defined quasiparticles and singular power-law behaviours in physical properties. We show that the Non-Fermi Liquid states found here are outside the known categories of Non-Fermi Liquid states in the conventional multi-channel Kondo problem. This work lays a novel ground for the identification of unexpected Non-Fermi Liquid phases in many strongly spin-orbital-coupled quantum materials.
Abhee K. Dutt-mazumder - One of the best experts on this subject based on the ideXlab platform.
-
Non-Fermi Liquid behavior of thermal relaxation time in degenerate electron plasma
Physical Review D, 2013Co-Authors: S. Sarkar, Abhee K. Dutt-mazumderAbstract:The thermal relaxation time (${\ensuremath{\tau}}_{{\ensuremath{\kappa}}_{\mathrm{ee}}}$) for the degenerate electron plasma has been calculated by incorporating Non-Fermi Liquid corrections both for the thermal conductivity and specific heat capacity. Perturbative results are presented by making expansion in $T/{m}_{D}$ with next to leading order corrections. We see that the next to leading order Non-Fermi Liquid corrections further reduce the decrease in relaxation time due to the leading order corrections.
-
Non-Fermi Liquid corrections to the neutrino mean free path in dense quark matter
Physical Review D, 2011Co-Authors: Kausik Pal, Abhee K. Dutt-mazumderAbstract:We calculate the neutrino mean free path with Non-Fermi Liquid (NFL) corrections in quark matter from scattering and absorption processes for both degenerate and nondegenerate neutrinos. We show that the mean free path decreases due to the Non-Fermi Liquid corrections leading to $l_{mean}^{-1}\sim[......+ .... C_F^2\alpha_s^2\ln(m_D/T)^2]$. These reduction results in higher rate of scattering.