Quantifying memory capacity as a quantum thermodynamic resource

• المؤلفون الرئيسيون: Narasimhachar, Varun, Thompson, Jayne, Ma, Jiajun, Gour, Gilad, Gu, Mile
• مؤلفون آخرون: School of Physical and Mathematical Sciences
• التنسيق: مقال
• اللغة: English
• منشور في: 2019
• الموضوعات: Quantum Optics; Memory Capacity; DRNTU::Science::Physics
• الوصول للمادة أونلاين: https://hdl.handle.net/10356/85422; http://hdl.handle.net/10220/48311
• المؤسسة: Nanyang Technological University

The information-carrying capacity of a memory is known to be a thermodynamic resource facilitating the conversion of heat to work. Szilard's engine explicates this connection through a toy example involving an energy-degenerate two-state memory. We devise a formalism to quantify the thermodynamic value of memory in general quantum systems with nontrivial energy landscapes. Calling this the thermal information capacity, we show that it converges to the nonequilibrium Helmholtz free energy in the thermodynamic limit. We compute the capacity exactly for a general two-state (qubit) memory away from the thermodynamic limit, and find it to be distinct from known free energies. We outline an explicit memory-bath coupling that can approximate the optimal qubit thermal information capacity arbitrarily well.