Measurement Induced Synthesis of Coherent Quantum Batteries

Area of Science:

• Quantum Thermodynamics
• Quantum Information Science
• Quantum Technology

Background:

• Quantum coherence and energy are crucial resources for quantum technologies and thermodynamics.
• These two properties, quantum coherence and energy, can exhibit a complementary relationship, where increasing one may decrease the other.
• Recent advancements have shown the potential for autonomously harvesting steady-state quantum coherence from cold environments.

Purpose of the Study:

• To propose a novel method for synthesizing quantum coherence from multiple independent two-level systems (TLS) into a single, more coherent system.
• To utilize a measurement process that simultaneously enhances both energy and quantum coherence.
• To conceptualize this measurement as a quantum Maxwell demon for creating a coherent quantum battery.

Main Methods:

• Conditional synthesis of N independent two-level systems (TLS) with partial quantum coherence.
• Employing a measurement strategy that increases both energy and coherence.
• Utilizing Positive Operator-Valued Measure (POVM) elements diagonal in the energy representation.
• Numerical optimization and proof-of-principle tests to evaluate synthesis strategies.

Main Results:

• Demonstration of a measurement process that synthesizes coherent energy from individual TLS into a large coherent quantum battery.
• The proposed measurement, while diagonal in energy representation, effectively harnesses coherence.
• Identification of efficient strategies for achieving high coherent energy in the quantum battery.
• Validation through numerical optimization and experimental proof-of-principle tests.

Conclusions:

• The proposed method offers a feasible 'repeat-until-success' approach for synthesizing coherent quantum batteries.
• This work opens avenues for harnessing steady-state autonomous coherence from cold environments.
• The findings contribute to the development of quantum batteries and the understanding of quantum energy resources.