Year: 2024
Type: preprint
Abstract: We consider a Su-Schrieffer-Heeger model in the assisted hopping limit, where direct electron hopping is subdominant. At fixed electron-phonon coupling and in the absence of Coulomb interactions, the model shows a deconfined quantum critical point (DQCP) between a $(π,0)$ valence bond solid in the adiabatic limit and a quantum antiferromagnetic (AFM) phase at high phonon frequencies. Here, we show that by adding terms to the model that reinforce the AFM phase, thereby lowering the critical phonon frequency, the quantum phase transition becomes strongly first order. Our results do not depend on the symmetry of the model. In fact, adding a Hubbard-$U$ term to the model lowers the O(4) symmetry of the model to SU(2) such that the DQCP we observe has the same symmetries as other models that account for similar quantum phase transitions.
Source: arXiv (Cornell University)
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: Friedrich-Alexander-Universität Erlangen-Nürnberg, Deutsche Forschungsgemeinschaft, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Gauss Centre for Supercomputing, Leibniz-Gemeinschaft, Leibniz-Rechenzentrum
Awards: G158081186, G1840770272, G2152757567, G2158694287, G2584274330, SFB 1170: Topologische und korrelierte Elektronik in Ober und Grenzflächen ("ToCoTronics"), G364537819, HochleistungscomputeCluster, G6203220346, EXC 2147: Komplexität und Topologie in Quantenmaterialien (CT.QMAT), G6690480278, G7144852284, G940488177
OpenAlex ID: W4405767686