Title: DMFT Reveals the Non-Hermitian Topology and Fermi Arcs in Heavy-Fermion Systems

Abstract

When a strongly correlated system supports well-defined quasiparticles, it allows for an elegant one-body effective description within the non-Hermitian topological theory. While the microscopic many-body Hamiltonian of a closed system remains Hermitian, the one-body quasiparticle Hamiltonian is non-Hermitian due to the finite quasiparticle lifetime. We use such a non-Hermitian description in the heavy-fermion two-dimensional systems with the momentum-dependent hybridization to reveal a fascinating phenomenon which can be directly probed by the spectroscopic measurements, the bulk “Fermi arcs.” Starting from a simple two-band model, we first combine the phenomenological approach with the perturbation theory to show the existence of the Fermi arcs and reveal their connection to the topological exceptional points, special points in the Brillouin zone where the Hamiltonian is nondiagonalizable. The appearance of such points necessarily requires that the electrons belonging to different orbitals have different lifetimes. This requirement is naturally satisfied in the heavy-fermion systems, where the itinerant c electrons experience much weaker interaction than the localized f electrons. We then utilize the dynamical mean field theory to numerically calculate the spectral function and confirm our findings. We show here that the concept of the exceptional points in the non-Hermitian quasiparticle Hamiltonians is a powerful tool for predictingmore » new phenomena in strongly correlated electron systems.« less

Authors:

Nagai, Yuki  ^[1];

• Search DOE PAGES for author "Nagai, Yuki"
• Search DOE PAGES for ORCID "0000-0001-5098-5440"

Qi, Yang  ^[2];

• Search DOE PAGES for author "Qi, Yang"
• Search DOE PAGES for ORCID "0000-0003-0678-9770"

Isobe, Hiroki ^[3]; Kozii, Vladyslav  ^[4];

• Search DOE PAGES for author "Kozii, Vladyslav"
• Search DOE PAGES for ORCID "0000-0002-0695-6500"

Fu, Liang ^[3]

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+ Show Author Affiliations

1. Japan Atomic Energy Agency (JAEA), Chiba (Japan); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2. Fudan Univ., Shanghai (China); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
3. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
4. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Publication Date:

Wed Nov 25 00:00:00 EST 2020

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; Japan Society for the Promotion of Science (JSPS); National Natural Science Foundation of China (NSFC)

OSTI Identifier:

1650097

Grant/Contract Number:  

AC02-05CH11231; 15K00178; 18K03552; JP16H00995; 18H04228; SC0010526; 11874115

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Letters

Additional Journal Information:

Journal Volume: 125; Journal Issue: 22; Journal ID: ISSN 0031-9007

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY