scholarly journals BCS superconductivity in quantum critical metals

2009 ◽  
Vol 80 (18) ◽  
Author(s):  
Jian-Huang She ◽  
Jan Zaanen
Keyword(s):  
Critical Metals ◽  
Quantum Critical

scholarly journals Identification of non-Fermi liquid fermionic self-energy from quantum Monte Carlo data

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Xiao Yan Xu ◽  
Avraham Klein ◽  
Kai Sun ◽  
Andrey V. Chubukov ◽  
Zi Yang Meng
Keyword(s):  
Monte Carlo ◽  
Finite Temperature ◽  
Quantum Monte Carlo ◽  
Fermi Liquid ◽  
Quantum Critical Point ◽  
Critical Metals ◽  
Monte Carlo Data ◽  
Low Frequencies ◽  
Self Energy ◽  
Quantum Critical

Abstract Quantum Monte Carlo (QMC) simulations of correlated electron systems provide unbiased information about system behavior at a quantum critical point (QCP) and can verify or disprove the existing theories of non-Fermi liquid (NFL) behavior at a QCP. However, simulations are carried out at a finite temperature, where quantum critical features are masked by finite-temperature effects. Here, we present a theoretical framework within which it is possible to separate thermal and quantum effects and extract the information about NFL physics at T = 0. We demonstrate our method for a specific example of 2D fermions near an Ising ferromagnetic QCP. We show that one can extract from QMC data the zero-temperature form of fermionic self-energy Σ(ω) even though the leading contribution to the self-energy comes from thermal effects. We find that the frequency dependence of Σ(ω) agrees well with the analytic form obtained within the Eliashberg theory of dynamical quantum criticality, and obeys ω2/3 scaling at low frequencies. Our results open up an avenue for QMC studies of quantum critical metals.

scholarly journals Observing the origin of superconductivity in quantum critical metals

2011 ◽  
Vol 84 (14) ◽  
Author(s):  
J.-H. She ◽  
B. J. Overbosch ◽  
Y.-W. Sun ◽  
Y. Liu ◽  
K. E. Schalm ◽  
...  
Keyword(s):  
Critical Metals ◽  
Quantum Critical

scholarly journals Incoherent transport in clean quantum critical metals

2015 ◽  
Vol 2015 (10) ◽  
Author(s):  
Richard A. Davison ◽  
Blaise Goutéraux ◽  
Sean A. Hartnoll
Keyword(s):  
Critical Metals ◽  
Quantum Critical ◽  
Incoherent Transport

scholarly journals Monte Carlo Studies of Quantum Critical Metals

2019 ◽  
Vol 10 (1) ◽  
pp. 63-84 ◽  
Author(s):  
Erez Berg ◽  
Samuel Lederer ◽  
Yoni Schattner ◽  
Simon Trebst
Keyword(s):  
Monte Carlo ◽  
Quantum Monte Carlo ◽  
High Temperature Superconductors ◽  
Density Wave ◽  
Spin Density Wave ◽  
Quantum Criticality ◽  
Critical Metals ◽  
Monte Carlo Studies ◽  
The Status ◽  
Quantum Critical

Metallic quantum critical phenomena are believed to play a key role in many strongly correlated materials, including high-temperature superconductors. Theoretically, the problem of quantum criticality in the presence of a Fermi surface has proven to be highly challenging. However, it has recently been realized that many models used to describe such systems are amenable to numerically exact solution by quantum Monte Carlo (QMC) techniques, without suffering from the fermion sign problem. In this review, we examine the status of the understanding of metallic quantum criticality and the recent progress made by QMC simulations. We focus on the cases of spin-density wave and Ising nematic criticality. We describe the results obtained so far and their implications for superconductivity, non-Fermi liquid behavior, and transport near metallic quantum critical points. Some of the outstanding puzzles and future directions are highlighted.

scholarly journals Local fluctuations in quantum critical metals

2003 ◽  
Vol 68 (11) ◽  
Author(s):  
Qimiao Si ◽  
Silvio Rabello ◽  
Kevin Ingersent ◽  
J. Lleweilun Smith
Keyword(s):  
Critical Metals ◽  
Local Fluctuations ◽  
Quantum Critical

scholarly journals Non-Fermi-liquid fixed point in a Wilsonian theory of quantum critical metals

2013 ◽  
Vol 88 (12) ◽  
Author(s):  
A. Liam Fitzpatrick ◽  
Shamit Kachru ◽  
Jared Kaplan ◽  
S. Raghu
Keyword(s):  
Fixed Point ◽  
Fermi Liquid ◽  
Critical Metals ◽  
Quantum Critical

scholarly journals Instabilities of quantum critical metals in the limit $N_f\rightarrow0$

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Petter Säterskog
Keyword(s):  
Fermi Surface ◽  
Long Range ◽  
Charge Density Wave ◽  
Order Parameter ◽  
Finite Interval ◽  
Density Wave ◽  
Parameter Fluctuation ◽  
Critical Metals ◽  
Quantum Critical Points ◽  
Quantum Critical

We study a model in 2+1 dimensions composed of a Fermi surface of N_fNf flavors of fermions coupled to scalar fluctuations near quantum critical points (QCPs). The N_f\rightarrow0Nf→0 limit allows us to non-perturbatively calculate the long-range behavior of fermion correlation functions. We use this to calculate charge, spin and pair susceptibilities near different QCPs at zero and finite temperatures, with zero and finite order parameter gaps. While fluctuations smear out the fermionic quasiparticles, we find QCPs where the overall effect of fluctuations leads to enhanced pairing. We also find QCPs where the fluctuations induce spin and charge density wave instabilities for a finite interval of order parameter fluctuation gaps at T=0T=0. We restore a subset of the diagrams suppressed in the N_f\rightarrow0Nf→0 limit, all diagrams with internal fermion loops with at most 2 vertices, and find that this does not change the long-range behavior of correlators except right at the QCPs.

scholarly journals Quantum critical metals ind=3+1dimensions

2013 ◽  
Vol 88 (11) ◽  
Author(s):  
R. Mahajan ◽  
D. M. Ramirez ◽  
S. Kachru ◽  
S. Raghu
Keyword(s):  
Critical Metals ◽  
Quantum Critical
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