Electron Density and Compressibility in the Kitaev Model with a Spatially Modulated Phase in the Superconducting Pairing

A current flowing through a one-dimensional Kitaev chain induces a spatial modulation in its superconducting pairing, characterized by a wavevector <i>Q</i>, which is known to induce two types of topological phase transitions: one is the customary band topology transition between gapped...

Full description

Saved in:
Bibliographic Details
Main Authors: Fabián G. Medina Cuy, Fabrizio Dolcini
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Condensed Matter
Subjects:
Online Access:https://www.mdpi.com/2410-3896/10/1/14
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850089899438374912
author Fabián G. Medina Cuy
Fabrizio Dolcini
author_facet Fabián G. Medina Cuy
Fabrizio Dolcini
author_sort Fabián G. Medina Cuy
collection DOAJ
description A current flowing through a one-dimensional Kitaev chain induces a spatial modulation in its superconducting pairing, characterized by a wavevector <i>Q</i>, which is known to induce two types of topological phase transitions: one is the customary band topology transition between gapped phases, while the other is a Lifshitz transition related to the Fermi surface topology and leading to a gapless superconducting phase. We investigate the behavior of the electron density <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>ρ</mi></semantics></math></inline-formula> and the compressibility <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>κ</mi></semantics></math></inline-formula> across the two types of transitions, as a function of the model parameters. We find that the behavior of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>ρ</mi></semantics></math></inline-formula> as a function of <i>Q</i> and chemical potential <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>μ</mi></semantics></math></inline-formula> enables one to infer the ground state phase diagram. Moreover, the analysis of the compressibility <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>κ</mi></semantics></math></inline-formula> as a function of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>μ</mi></semantics></math></inline-formula> enables one to distinguish the two transitions: While <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>κ</mi></semantics></math></inline-formula> exhibits a symmetric divergence across the band topology transition, it displays an asymmetric jump across the Lifshitz transition.
format Article
id doaj-art-decff77ba36b4617952b905f33e68156
institution DOAJ
issn 2410-3896
language English
publishDate 2025-02-01
publisher MDPI AG
record_format Article
series Condensed Matter
spelling doaj-art-decff77ba36b4617952b905f33e681562025-08-20T02:42:40ZengMDPI AGCondensed Matter2410-38962025-02-011011410.3390/condmat10010014Electron Density and Compressibility in the Kitaev Model with a Spatially Modulated Phase in the Superconducting PairingFabián G. Medina Cuy0Fabrizio Dolcini1Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, ItalyDipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, ItalyA current flowing through a one-dimensional Kitaev chain induces a spatial modulation in its superconducting pairing, characterized by a wavevector <i>Q</i>, which is known to induce two types of topological phase transitions: one is the customary band topology transition between gapped phases, while the other is a Lifshitz transition related to the Fermi surface topology and leading to a gapless superconducting phase. We investigate the behavior of the electron density <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>ρ</mi></semantics></math></inline-formula> and the compressibility <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>κ</mi></semantics></math></inline-formula> across the two types of transitions, as a function of the model parameters. We find that the behavior of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>ρ</mi></semantics></math></inline-formula> as a function of <i>Q</i> and chemical potential <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>μ</mi></semantics></math></inline-formula> enables one to infer the ground state phase diagram. Moreover, the analysis of the compressibility <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>κ</mi></semantics></math></inline-formula> as a function of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>μ</mi></semantics></math></inline-formula> enables one to distinguish the two transitions: While <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>κ</mi></semantics></math></inline-formula> exhibits a symmetric divergence across the band topology transition, it displays an asymmetric jump across the Lifshitz transition.https://www.mdpi.com/2410-3896/10/1/14Kitaev modeltopological superconductorsp-wave superconductivitytopological transitionsLifshitz transitions
spellingShingle Fabián G. Medina Cuy
Fabrizio Dolcini
Electron Density and Compressibility in the Kitaev Model with a Spatially Modulated Phase in the Superconducting Pairing
Condensed Matter
Kitaev model
topological superconductors
p-wave superconductivity
topological transitions
Lifshitz transitions
title Electron Density and Compressibility in the Kitaev Model with a Spatially Modulated Phase in the Superconducting Pairing
title_full Electron Density and Compressibility in the Kitaev Model with a Spatially Modulated Phase in the Superconducting Pairing
title_fullStr Electron Density and Compressibility in the Kitaev Model with a Spatially Modulated Phase in the Superconducting Pairing
title_full_unstemmed Electron Density and Compressibility in the Kitaev Model with a Spatially Modulated Phase in the Superconducting Pairing
title_short Electron Density and Compressibility in the Kitaev Model with a Spatially Modulated Phase in the Superconducting Pairing
title_sort electron density and compressibility in the kitaev model with a spatially modulated phase in the superconducting pairing
topic Kitaev model
topological superconductors
p-wave superconductivity
topological transitions
Lifshitz transitions
url https://www.mdpi.com/2410-3896/10/1/14
work_keys_str_mv AT fabiangmedinacuy electrondensityandcompressibilityinthekitaevmodelwithaspatiallymodulatedphaseinthesuperconductingpairing
AT fabriziodolcini electrondensityandcompressibilityinthekitaevmodelwithaspatiallymodulatedphaseinthesuperconductingpairing