A qubit regularization of asymptotic freedom without fine-tuning

• Published in: arXiv.org
• Main Authors: Maiti, Sandip, Banerjee, Debasish, Chandrasekharan, Shailesh, Marina Krstic Marinkovic
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 15.01.2024
• Subjects: Asymptotic properties; Fixed points (mathematics); Hilbert space; Phase transitions; Physics - High Energy Physics - Lattice; Physics - High Energy Physics - Theory; Physics - Quantum Physics; Physics - Strongly Correlated Electrons; Quantum theory; Qubits (quantum computing); Regularization
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2401.10157

Other than the commonly used Wilson's regularization of quantum field theories (QFTs), there is a growing interest in regularizations that explore lattice models with a strictly finite local Hilbert space, in anticipation of the upcoming era of quantum simulations of QFTs. A notable example is Euclidean qubit regularization, which provides a natural way to recover continuum QFTs that emerge via infrared fixed points of lattice theories. Can such regularizations also capture the physics of ultraviolet fixed points? We present a novel regularization of the asymptotically free massive continuum QFT that emerges at the Berezenski-Kosterlitz-Thouless (BKT) transition through a hard core loop-gas model, discussing the advantages this model provides compared to traditional regularizations. In particular, we demonstrate that without the need for fine-tuning, it can reproduce the universal step-scaling function of the classical lattice XY model in the massive phase as we approach the phase transition.