Geometry of Contact Terms in Linear Response: Applications to Elasticity

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Osborne, Ian, Monteiro, Gustavo, Bradlyn, Barry
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866915851679039488
author Osborne, Ian
Monteiro, Gustavo
Bradlyn, Barry
author_facet Osborne, Ian
Monteiro, Gustavo
Bradlyn, Barry
contents Employing the Kubo linear response formalism to calculate the elasticity of anisotropic systems has been shown to yield odd elastic moduli. For Hamiltonian systems, this result seems to be contradictory as it would violate energy conservation. To resolve this discrepancy, we examine the predictions of quantum linear response in the context of our expectation from classical elasticity theory. Our framework reveals that the geometry of the space of strain perturbations introduces correction factors to the correspondence between the Kubo formula and the elastic moduli which resolves the contradiction. We use a two-dimensional gas of electrons in a magnetic field as a pedagogical example. We use generalized f-sum rules to demonstrate how contact terms may reveal themselves in experimental measurements. Finally, we discuss the implications of our results for interpreting more general linear response functions.
format Preprint
id arxiv_https___arxiv_org_abs_2603_10144
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Geometry of Contact Terms in Linear Response: Applications to Elasticity
Osborne, Ian
Monteiro, Gustavo
Bradlyn, Barry
Mesoscale and Nanoscale Physics
Quantum Gases
Statistical Mechanics
Employing the Kubo linear response formalism to calculate the elasticity of anisotropic systems has been shown to yield odd elastic moduli. For Hamiltonian systems, this result seems to be contradictory as it would violate energy conservation. To resolve this discrepancy, we examine the predictions of quantum linear response in the context of our expectation from classical elasticity theory. Our framework reveals that the geometry of the space of strain perturbations introduces correction factors to the correspondence between the Kubo formula and the elastic moduli which resolves the contradiction. We use a two-dimensional gas of electrons in a magnetic field as a pedagogical example. We use generalized f-sum rules to demonstrate how contact terms may reveal themselves in experimental measurements. Finally, we discuss the implications of our results for interpreting more general linear response functions.
title Geometry of Contact Terms in Linear Response: Applications to Elasticity
topic Mesoscale and Nanoscale Physics
Quantum Gases
Statistical Mechanics
url https://arxiv.org/abs/2603.10144