Supersolid Phase in the Diluted Holstein Model

Fuente: arXiv
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Autori principali: Meng, Jingyao, Zhang, Yuxi, Fernandes, Rafael M., Ma, Tianxing, Scalettar, R. T.
Natura: Preprint
Pubblicazione: 2024
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author Meng, Jingyao
Zhang, Yuxi
Fernandes, Rafael M.
Ma, Tianxing
Scalettar, R. T.
author_facet Meng, Jingyao
Zhang, Yuxi
Fernandes, Rafael M.
Ma, Tianxing
Scalettar, R. T.
contents The Holstein model on a square lattice at half-filling has a well-established finite temperature phase transition to an insulating state with long range charge density wave (CDW) order. Because this CDW formation suppresses pairing, a superconducting (SC) phase emerges only with doping. In this work, we study the effects of dilution of the local phonon degrees of freedom in the Holstein model while keeping the system at half filling. We find not only that the CDW remains present up to a dilution fraction $f \sim 0.15$, but also that long range pairing is stabilized with increasing $f$, resulting in a {\it supersolid} regime centered at $f \approx 0.10$, where long range diagonal and off-diagonal correlations coexist. Further dilution results in a purely SC phase, and ultimately in a normal metal. Our results provide a new route to the supersolid phase via the introduction of impurities at fixed positions which both increase quantum fluctuations and also are immune to the competing tendency to phase separation often observed in the doped case.
format Preprint
id arxiv_https___arxiv_org_abs_2407_02239
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Supersolid Phase in the Diluted Holstein Model
Meng, Jingyao
Zhang, Yuxi
Fernandes, Rafael M.
Ma, Tianxing
Scalettar, R. T.
Strongly Correlated Electrons
The Holstein model on a square lattice at half-filling has a well-established finite temperature phase transition to an insulating state with long range charge density wave (CDW) order. Because this CDW formation suppresses pairing, a superconducting (SC) phase emerges only with doping. In this work, we study the effects of dilution of the local phonon degrees of freedom in the Holstein model while keeping the system at half filling. We find not only that the CDW remains present up to a dilution fraction $f \sim 0.15$, but also that long range pairing is stabilized with increasing $f$, resulting in a {\it supersolid} regime centered at $f \approx 0.10$, where long range diagonal and off-diagonal correlations coexist. Further dilution results in a purely SC phase, and ultimately in a normal metal. Our results provide a new route to the supersolid phase via the introduction of impurities at fixed positions which both increase quantum fluctuations and also are immune to the competing tendency to phase separation often observed in the doped case.
title Supersolid Phase in the Diluted Holstein Model
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2407.02239