Collectively enhanced thermalization via multiqubit collisions

Area of Science:

• Quantum Information Science
• Quantum Many-Body Physics
• Quantum Thermodynamics

Background:

• Understanding qubit evolution under environmental interactions is crucial for quantum computing.
• The dynamics of a target qubit interacting with multiple quantum systems (N-qubit clusters) are complex.
• Previous studies have explored various bath models, but novel interaction regimes are of interest.

Purpose of the Study:

• To investigate the evolution of a target qubit interacting with N-qubit clusters.
• To identify conditions leading to effective thermal bath, coherent drive, or squeezed bath interactions.
• To explore the potential for quantum advantage in qubit thermalization dynamics.

Main Methods:

• Simulating the interaction between a single target qubit and N-qubit clusters.
• Analyzing the resulting qubit dynamics under different cluster states.
• Characterizing the effective bath interactions experienced by the target qubit.

Main Results:

• The target qubit's evolution can mimic interaction with a thermal bath, coherent drive, or squeezed bath depending on the cluster state.
• A phenomenon termed 'quantum superthermalization' is observed, where qubit temperature scales with N^2.
• Thermalization time is reduced proportionally to N, with appropriate nonthermal preparation of cluster coherence.

Conclusions:

• Quantum superthermalization offers a pathway to enhanced qubit control and faster thermalization.
• This effect demonstrates a scalable quantum advantage in controlling qubit dynamics.
• Experimental realization of quantum superthermalization is feasible and suggested.