Work Statistics and Entanglement Across the Fermionic Superfluid-Insulator Transition

Author(s)

Zawadzki, Krissia ; Canella, Guilherme A. ; Franca, Vivian V. ; D'Amico, Irene

• Document type: Journal article
• Source: ADVANCED QUANTUM TECHNOLOGIES; v. 7, n. 3, p. 11-pg., 2024-01-20.

Abstract

Entanglement in many-body systems may display quantum phase transition signatures, and analogous insights are emerging in the study of work fluctuations. Here, the fermionic superfluid-to-insulator transition (SIT) is considered and related to its entanglement properties and its work distribution statistics. Using the attractive fermionic Hubbard model with randomly distributed impurities, the work distribution is analyzed under two quench protocols triggering the SIT. In the first, the concentration of impurities is increased; in the second, the impurities' disorder strength is varied. The results indicate that, at criticality, the entanglement is minimized while the average work is maximized. This study demonstrates that, for this state, density fluctuations vanish at all orders, resulting in all central moments of the work probability distribution being precisely zero. For systems undergoing a precursor to the transition (short chains with finite impurity potential) numerical results confirm these predictions, with higher moments further from the ideal results. For both protocols, at criticality, the system absorbs the most energy with almost no penalty in terms of fluctuations: ultimately this feature can be used to implement a quantum critical battery. The impact of temperature on this critical behaviour is also investigated and shown to favor work extraction for high enough temperatures. Small quantum systems can become hardware for quantum thermal machines. They may display quantum correlations and critical behavior, both affecting energetic properties. Here, thermodynamic processes across the superfluid-to-insulator transition are studied. At criticality, the vanishing of density fluctuations simultaneously minimizes the entanglement and maximizes the average work. Ultimately, this feature can be used to implement a quantum critical battery.image (AU)

• FAPESP's process: 21/06744-8 - Quantum phase transitions in nanomaterials: developing of density functionals and their applications via DFT
• Grantee: Vivian Vanessa França Henn
• Support Opportunities: Research Grants - Young Investigators Grants - Phase 2
• FAPESP's process: 22/05198-2 - Measuring and tracing adiabaticity in many-body quantum systems
• Grantee: Luiz Nunes de Oliveira
• Support Opportunities: Research Grants - Visiting Researcher Grant - International