Thinking locally: Reflections on Dynamical Mean‐Field Theory from a high‐temperature/high‐energy perspective

Georges, Antoine

doi:10.1002/andp.201100042

Cited by 14 publications

(12 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This also means that DMFT based on a local self-consistent approximation can become very accurate in this high-temperature limit. For instance, high-temperature expansions for the three-dimensional Hubbard model agree well with DMFT calculations for thermodynamical quantities, and this remains the case down to temperatures of the order T W/8 [65,67]. One should, however, note that the self-energy of the three-dimensional Hubbard model does not become completely k independent even in the limit T → ∞ [68].…”

Section: Features Of the Spectral Functions And Self-energymentioning

confidence: 75%

See 1 more Smart Citation

Local origin of the pseudogap in the attractive Hubbard model

Peters

Bauer

2015

Phys. Rev. B

View full text Add to dashboard Cite

We provide a new perspective on the pseudogap physics for attractive fermions as described by the three-dimensional Hubbard model. The pseudogap in the single-particle spectral function, which occurs for temperatures above the critical temperature $T_c$ of the superfluid transition, is often interpreted in terms of preformed, uncondensed pairs. Here we show that the occurrence of pseudogap physics can be consistently understood in terms of local excitations which lead to a splitting of the quasiparticle peak for sufficiently large interaction. This effect becomes prominent at intermediate and high temperatures when the quantum mechanical hopping is incoherent. We clarify the existence of a conjectured temperature below which pseudogap physics is expected to occur. Our results are based on approximating the physics of the three-dimensional Hubbard model by dynamical mean field theory calculations and a momentum independent self-energy. Our predictions can be tested with ultracold atoms in optical lattices with currently available temperatures and spectroscopic techniques.Comment: 15 pages including appendix; suggestions for further references welcom

show abstract

Section: Features Of the Spectral Functions And Self-energymentioning

confidence: 75%

“…Let us first note that in the limit of high temperature T W,U correlation lengths become small and the physics is dominated by local processes [65]. This is seen, for instance, when we consider the bare single-particle propagator in imaginary time:…”

Section: Features Of the Spectral Functions And Self-energymentioning

confidence: 98%

Local origin of the pseudogap in the attractive Hubbard model

Peters

Bauer

2015

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…This important question can, in principle, be investigated by computing systematic nonlocal corrections to single-site DMFT, a research direction already investigated by several authors. [31][32][33]64 The recent work already provides some evidence that for a Hubbard model on a square lat-tice the nonlocal corrections are very small well above the coexistence dome (at T T c ) 64 and esentially negligible for frustrated triangular lattice. 33 On the experimental side, the possible role of nonlocal effects such as spinons can be investigated by systematic studies of a series of materials with varying degrees of magnetic frustration.…”

Section: Discussionmentioning

confidence: 99%

“…16,17 The DMFT provides a unique theoretical framework, as it works well in the entire range of model parameters, thus treating all the relevant phases and regimes on an equal footing. It is, however, most reliable at high temperatures, [31][32][33][34] when the correlations are more local, and this is precisely the regime of primary interest of this paper. To solve the DMFT equations we utilize both the iterated perturbation theory 16 (IPT) and the numerically exact continuous time quantum Monte Carlo (CTQMC).…”

Section: Phase Diagrammentioning

confidence: 99%

Finite-temperature crossover and the quantum Widom line near the Mott transition

et al. 2013

View full text Add to dashboard Cite

The experimentally established phase diagram of the half-filled Hubbard model features the existence of three distinct finite-temperature regimes, separated by extended crossover regions. A number of crossover lines can be defined to span those regions, which we explore in quantitative detail within the framework of dynamical mean-field theory. Most significantly, the high temperature crossover between the bad metal and Mott-insulator regimes displays a number of phenomena marking the gradual development of the Mott insulating state. We discuss the quantum critical scaling behavior found in this regime, and propose methods to facilitate its possible experimental observation. We also introduce the concept of quantum Widom lines and present a detailed discussion that highlights its physical meaning when used in the context of quantum phase transitions.

show abstract

“…Real materials, of course, exist in finite (low) dimensions where systematic corrections to DMFT need to be included [36][37][38][39]. In many cases [40][41][42], these nonlocal corrections prove significant only at sufficiently low temperatures. Then our findings should be even quantitatively accurate in the high-temperature incoherent regime, as in the very recent experiments on organic materials [43] for the case of half-filling.…”

mentioning

confidence: 99%

Bad-Metal Behavior Reveals Mott Quantum Criticality in Doped Hubbard Models

et al. 2015

View full text Add to dashboard Cite

Bad-Metal (BM) behavior featuring linear temperature dependence of the resistivity extending to well above the Mott-Ioffe-Regel (MIR) limit is often viewed as one of the key unresolved signatures of strong correlation. Here we associate the BM behavior with the Mott quantum criticality by examining a fully frustrated Hubbard model where all long-range magnetic orders are suppressed, and the Mott problem can be rigorously solved through Dynamical Mean-Field Theory. We show that for the doped Mott insulator regime, the coexistence dome and the associated first-order Mott metal-insulator transition are confined to extremely low temperatures, while clear signatures of Mott quantum criticality emerge across much of the phase diagram. Remarkable scaling behavior is identified for the entire family of resistivity curves, with a quantum critical region covering the entire BM regime, providing not only insight, but also quantitative understanding around the MIR limit, in agreement with the available experiments.PACS numbers: 71.27.+a,71.30.+h Metallic transport inconsistent with Fermi liquid theory has been observed in many different systems; it is often linked to quantum criticality around some ordering phase transition [1, 2]. Such behavior is notable near quantum critical points in good conductors, for example in heavy fermion compounds [3, 4]. In several other classes of materials, however, much more dramatic departures form conventional metallic behavior are clearly observed, where resistivity still rises linearly with temperature, but it reaches paradoxically large values, well past the MIR limit [5, 6]. This "Bad-Metal" (BM) behavior [7], was first identified in the heyday of high-temperature superconductivity, in materials such as La 2−x Sr x CuO 4 [8]. While the specific copper-oxide family and related high-T c materials remain ill-understood and marred with controversy, it soon became clear that BM behavior is a much more general feature [6] of materials close to the Mott metal-insulator transition (MIT) [9]. Indeed, it has been clearly identified also in various oxides [10, 11], organic Mott systems [12][13][14], as well as more recently discovered families of iron pnictides [15]. Despite years of speculation and debate, so far its clear physical interpretation has not been established.To gain reliable insight into the origin of BM behavior, it is useful to examine an exactly solvable model system, where one can suppress all possible effect associated with the approach to some broken symmetry phase, or those specific to low dimensions and a given lattice structure. This can be achieved by focusing on the "maximally frustrated Hubbard model", where an exact solution can be obtained by solving Dynamical Mean-Field Theory (DMFT) equations [16] in the paramagnetic phase. Although various aspects of the DMFT equation have been studied for more than twenty years, only very recent work [17,18] established how to identify the quantum critical (QC) behavior associated with the interaction-driven Mott transition at ...

show abstract

Thinking locally: Reflections on Dynamical Mean‐Field Theory from a high‐temperature/high‐energy perspective

Cited by 14 publications

References 34 publications

Local origin of the pseudogap in the attractive Hubbard model

Local origin of the pseudogap in the attractive Hubbard model

Finite-temperature crossover and the quantum Widom line near the Mott transition

Bad-Metal Behavior Reveals Mott Quantum Criticality in Doped Hubbard Models

Contact Info

Product

Resources

About