Bound on resistivity in flat-band materials due to the quantum metric

Autor:	Johannes Mitscherling, Tobias Holder
Rok vydání:	2022
Předmět:	Condensed Matter - Strongly Correlated Electrons Strongly Correlated Electrons (cond-mat.str-el) Condensed Matter - Mesoscale and Nanoscale Physics Mesoscale and Nanoscale Physics (cond-mat.mes-hall) FOS: Physical sciences Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
Zdroj:	Physical Review B. 105
ISSN:	2469-9969 2469-9950
DOI:	10.1103/physrevb.105.085154
Popis:	The quantum metric is a central quantity of band theory but has so far not been related to many response coefficients due to its nonclassical origin. However, within a newly developed Kubo formalism for fast relaxation, the decomposition of the dc electrical conductivity into both classical (intraband) and quantum (interband) contributions recently revealed that the interband part is proportional to the quantum metric. Here, we show that interband effects due to the quantum metric can be significantly enhanced and even dominate the conductivity for semimetals at charge neutrality and for systems with highly quenched bandwidth. This is true in particular for topological flat-band materials of nonzero Chern number, where for intermediate relaxation rates an upper bound exists for the resistivity due to the common geometrical origin of quantum metric and Berry curvature. We suggest to search for these effects in highly tunable rhombohedral trilayer graphene flakes. 10 pages, 5 figures
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::df9a0eb9c23aba153bb27dcc1121c0e1 https://doi.org/10.1103/physrevb.105.085154 Zobrazit plný text záznamu