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How two spins can thermalize a third spin.
Stephan Kleinbölting1, Rochus Klesse1
1Institut für Theoretische Physik, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany.
Summary
A single quantum spin 1/2 can be fully thermalized by a minimal bath of two entangled spins 1/2. This finding advances understanding of quantum thermalization and minimal bath requirements.
Area of Science:
- Quantum mechanics
- Statistical mechanics
- Condensed matter physics
Background:
- Quantum systems require thermal baths for thermalization.
- The minimal size of such baths is an open question.
Purpose of the Study:
- To determine the minimum bath size needed for quantum thermalization.
- To investigate thermalization using a specific scheme with Heisenberg exchange interaction.
Main Methods:
- Considering a single spin 1/2 as the system.
- Utilizing a bath of two initially entangled spin 1/2 particles.
- Applying a Heisenberg exchange interaction between the system and one bath spin.
Main Results:
- Demonstrated full thermalization of the single spin 1/2 system.
- Identified a minimal bath size of two spin 1/2 particles.
- Established a single integral constraint on the time-dependent coupling strength.
Conclusions:
- A bath of two entangled spins 1/2 is sufficient for thermalizing a single spin 1/2 system.
- The findings provide insights into the fundamental requirements for quantum thermalization.
- A generalized model for arbitrary numbers of spin 1/2 pairs in the bath was presented.
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