Two-Dimensional Non-Fermi-Liquid Metals: A Solvable Large-N Limit
| Autor: | Jeremias Aguilera Damia, Gonzalo Torroba, Srinivas Raghu, Shamit Kachru |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
High Energy Physics - Theory
Adjoint representation General Physics and Astronomy FOS: Physical sciences quantum critical point 01 natural sciences Superconductivity (cond-mat.supr-con) purl.org/becyt/ford/1 [https] Condensed Matter - Strongly Correlated Electrons Quantum critical point 0103 physical sciences non-fermi liquids large N limit 010306 general physics Mathematical physics Boson Physics Strongly Correlated Electrons (cond-mat.str-el) Condensed Matter - Superconductivity Order (ring theory) Fermion purl.org/becyt/ford/1.3 [https] High Energy Physics - Theory (hep-th) Exponent Quasiparticle Condensed Matter::Strongly Correlated Electrons Fermi liquid theory |
| Zdroj: | CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| DOI: | 10.1103/PhysRevLett.123.096402 |
| Popis: | Significant effort has been devoted to the study of "non-Fermi liquid" (NFL) metals: gapless conducting systems that lack a quasiparticle description. One class of NFL metals involves a finite density of fermions interacting with soft order parameter fluctuations near a quantum critical point. The problem has been extensively studied in a large N limit (N corresponding to the number of fermion flavors) where universal behavior can be obtained by solving a set of coupled saddle-point equations. However a remarkable study by S.-S.~Lee revealed the breakdown of such approximations in two spatial dimensions. We show that an alternate approach, in which the fermions belong to the fundamental representation of a global SU(N) flavor symmetry, while the order parameter fields transform under the adjoint representation (a "matrix large N" theory), yields a tractable large N limit. At low energies, the system consists of an overdamped boson with dynamical exponent $z=3$ coupled to a non-Fermi liquid with self energy $\Sigma(\omega) \sim \omega^{2/3}$, consistent with previous studies. Comment: 8 pages, two columns, 2 figures |
| Databáze: | OpenAIRE |
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