Schwinger model at finite temperature and density with beta VQE

2022/05/18 by Akio Tomiya, Tomiya, Akio
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Nuclear Theory (nucl-th) #Physics of Superconductivity and Magnetism #Quantum Physics (quant-ph)

paper · pdf · doi:10.48550/arxiv.2205.08860

openalex publication_date 2022/05/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We investigate a quantum gauge theory at finite temperature and density using a variational algorithm for near-term quantum devices. We adapt β-VQE to evaluate thermal and quantum expectation values and study the phase diagram for massless Schwinger model along with the temperature and density. By compering the exact variational free energy, we find the variational algorithm work for T>0 and μ>0 for the Schwinger model. No significant volume dependence of the variational free energy is observed in μ/g ∈[0, 1.4]. We calculate the chiral condensate and take the continuum extrapolation. As a result, we obtain qualitative picture of the phase diagram for massless Schwinger model.

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