Creation and Destruction of Coherence by Quantum Channels

Explore the intricacies of quantum coherence creation and destruction through quantum channels in this comprehensive 48-minute seminar by Dr. Masaya Takahashi from Centrum Fizyki Teoretycznej PAN. Begin with a qualitative perspective on decoherence using a phase-damping channel example on one qubit. Delve into the resource theory of coherence, examining its basic framework and notions. Investigate the cohering power and generalized cohering power of channels, understanding their operational significance in simulating channels with incoherent operations. Learn how quantum coherence in a state plus incoherent operations can be regarded as a quantum channel. Discover the concept of coherence generating capacity and its relationship to complete cohering power. Examine the equality between complete cohering power and generalized cohering power, as well as the introduction of completed decohering power. Analyze cases where entanglement between system and environment enhances decoherence, contrasting with coherence creation. Conclude with potential future applications in the field of quantum information and quantum computing.