Universal Anti-Kibble-Zurek Scaling in Fully Connected Systems

Area of Science:

• Quantum physics
• Condensed matter physics
• Statistical mechanics

Background:

• Quantum phase transitions (QPTs) are fundamental changes in quantum systems at absolute zero temperature.
• The Kibble-Zurek mechanism (KZM) describes defect formation during quenches across QPTs in isolated systems.
• Open quantum systems interact with their environment, altering dynamics.

Purpose of the Study:

• To investigate quench dynamics in open quantum systems undergoing a quantum phase transition.
• To explore the breakdown of the Kibble-Zurek mechanism in the presence of environmental interactions.
• To identify universal scaling laws in the anti-Kibble-Zurek regime.

Main Methods:

• Analysis of quench dynamics in open quantum systems.
• Theoretical modeling of quantum phase transitions.
• Investigation of system-environment interactions.
• Application to fully connected models like the quantum Rabi and Lipkin-Meshkov-Glick models.

Main Results:

• Kibble-Zurek scaling laws break down in open quantum systems.
• An 'anti-Kibble-Zurek' behavior emerges, where slower quenches lead to non-adiabatic dynamics.
• Universal anti-Kibble-Zurek scaling is demonstrated, determined by equilibrium critical exponents.
• Singular behavior in excited states of fully connected models is crucial for this universality.

Conclusions:

• System-environment interactions can lead to novel universal scaling laws in critical quantum systems.
• The anti-Kibble-Zurek scaling provides a new perspective on non-equilibrium dynamics in open quantum systems.
• Findings are relevant for understanding quantum criticality and decoherence in realistic quantum devices.