Boson-exchange parquet solver for dual fermions

Physical review. B./Physical review. B, Journal Year: 2020, Volume and Issue: 102(19)

Published: Nov. 18, 2020

We present and implement a parquet approximation within the dual-fermion formalism based on partial bosonization of dual vertex function which substantially reduces computational cost calculation. The method relies splitting exactly into single-boson exchange contributions residual four-fermion vertex, physically embody respectively long-range short-range spatial correlations. After recasting equations in terms these are solved using truncated unity Eckhardt et al. [Phys. Rev. B 101, 155104 (2020)], allows for rapid convergence with number form factors different regimes. While our numerical treatment can be restricted to only few Matsubara frequencies, reminiscent Astretsov 075109 one- two-particle spectral information is fully retained. In applications two-dimensional Hubbard model agrees quantitatively stochastic summation diagrams over wide range parameters.

Language: Английский

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Charge transport in the Hubbard model at high temperatures: Triangular versus square lattice

Physical review. B./Physical review. B, Journal Year: 2020, Volume and Issue: 102(11)

Published: Sept. 21, 2020

High-temperature bad-metal transport has been recently studied both theoretically and in experiments as one of the key signatures strong electronic correlations. Here we use dynamical mean field theory its cluster extensions, well finite-temperature Lanczos method to explore influence lattice frustration on thermodynamic properties Hubbard model at high temperatures. We consider triangular square lattices half-filling 15% hole doping. find that for $T\ensuremath{\gtrsim}1.5t$ self-energy becomes practically local, while finite-size effects become small size $4\ifmmode\times\else\texttimes\fi{}4$ types doping levels. The vertex corrections optical conductivity, which are significant even temperatures, contribute less lattice. approximately linear temperature dependence dc resistivity doped Mott insulator lattices.

Language: Английский

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A perspective on machine learning and data science for strongly correlated electron problems

Carbon Trends, Journal Year: 2022, Volume and Issue: 9, P. 100231 - 100231

Published: Oct. 1, 2022

Numerical approaches to the correlated electron problem have achieved considerable success, yet are still constrained by several bottlenecks, including high order polynomial or exponential scaling in system size, long autocorrelation times, challenges recognizing novel phases, and Fermion sign problem. Methods machine learning (ML), artificial intelligence, data science promise help address these limitations open up a new frontier strongly quantum simulations. In this paper, we review some of progress area. We begin examining context classical models, where their underpinnings application can be easily illustrated benchmarked. then discuss cases ML methods enabled scientific discovery. Finally, will examine applications accelerating model solutions state-of-the-art many-body like Monte Carlo potential future research directions.

Language: Английский

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T -linear resistivity, optical conductivity, and Planckian transport for a holographic local quantum critical metal in a periodic potential

Physical review. B./Physical review. B, Journal Year: 2023, Volume and Issue: 108(12)

Published: Sept. 26, 2023

High-${T}_{c}$ cuprate strange metals are characterized by a DC resistivity that scales linearly with $T$ from the onset of superconductivity to crystal melting temperature, current life time ${\ensuremath{\tau}}_{\ensuremath{\hbar}}\ensuremath{\simeq}\ensuremath{\hbar}/({k}_{B}T)$, ``Planckian dissipation''. At same time, optical conductivity ceases be Drude form at high temperatures, suggesting change underlying dynamics surprisingly leaves $T$-linear unaffected. We use AdS/CFT correspondence describes strongly coupled, densely many-body entangled metallic states matter study thermoelectrical transport properties and conductivities local quantum critical Gubser-Rocha holographic metal in $2+1$ dimensions presence lattice potential, prime candidate compare experiment. find electrical is linear low temperatures for large range potential strengths wave vectors, even as it transitions between different dissipative regimes. weak evolves function increasing temperature ``bad metal'' mid-IR resonance without changing transport, similar seen metals. This peak notably its evolution can fully understood consequence umklapp hydrodynamics: i.e., hydrodynamic perturbations Bloch modes lattice. strong an ``incoherent realized instead where momentum conservation no longer plays role transport. confirm this regime thermal diffusivity appears insensitive breaking translations explained Planckian dissipation originating universal microscopic chaos. A behavior has been found homogeneous relaxation. The charge does not submit chaos explanation, though continuing linear-in-$T$ saturates apparent slope, numerically equal rate.

Language: Английский

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Mapping the metal-insulator phase diagram by algebraically fast-forwarding dynamics on a cloud quantum computer

Physical Review Research, Journal Year: 2023, Volume and Issue: 5(2)

Published: June 27, 2023

Dynamical mean-field theory (DMFT) maps the local Green's function of Hubbard model to that Anderson impurity and thus gives an approximate solution from a simpler quantum model. Accurate solutions nonetheless become intractable for large systems. Quantum hybrid quantum-classical algorithms have been proposed efficiently solve models by preparing evolving ground state under Hamiltonian on computer is assumed scalability accuracy far beyond current state-of-the-art hardware. As proof principle demonstration targeting we, first time, close DMFT loop with noisy With highly optimized fast-forwarding circuit noise-resilient spectral analysis we observe both metallic Mott-insulating phases. Based Cartan decomposition, our algorithm fixed depth, fast-forwarding, can evolve initial over arbitrarily long times without time-discretization errors typical other product decomposition formulas such as Trotter decomposition. By exploiting structure circuits reduce gate count (to 77 cnots after optimization), simulate dynamics, extract frequencies We then demonstrate Mott transition mapping phases metal-insulator phase diagram. Near transition, method maintains where error would otherwise dominate due long-time evolution required resolve quasiparticle resonance frequency extremely zero. This work presents computation sides using digital hardware, made viable in terms simulation error, runtime To inform future computations analyze versus time domain. Both algebraic decompositions mitigation techniques adopted could be applied attempt correlated electronic phenomena computers.

Language: Английский

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