Speeding-up a quantum refrigerator via counter-diabatic driving

Multi-spin counter-diabatic driving in many-body quantum Otto refrigerators

Quantum refrigerators pump heat from a cold to a hot reservoir. In the few-particle regime, counter-diabatic (CD) driving of, originally adiabatic, work-exchange strokes is a promising candidate to overcome the bottleneck of vanishing cooling power. Here, we present a finite-time many-body quantum refrigerator that yields finite cooling power at high coefficient of performance, that considerably outperforms its non-adiabatic counterpart. We employ multi-spin CD driving and numerically investigate the scaling behavior of the refrigeration performance with system size. We further prove that opti…

Generalized Shortcuts to Adiabaticity and Enhanced Robustness Against Decoherence

Shortcuts to adiabaticity provide a general approach to mimic adiabatic quantum processes via arbitrarily fast evolutions in Hilbert space. For these counter-diabatic evolutions, higher speed comes at higher energy cost. Here, the counter-diabatic theory is employed as a minimal energy demanding scheme for speeding up adiabatic tasks. As a by-product, we show that this approach can be used to obtain infinite classes of transitionless models, including time-independent Hamiltonians under certain conditions over the eigenstates of the original Hamiltonian. We apply these results to investigate s…

分数频率下的动力学相位与量子热

Dynamical phase and quantum heat at fractional frequencies

本文展示了连续驱动下qubit发射功率随频率呈现分数频率共振峰的量子热现象，源于动力学相位积累，其位置与驱动形式等无关，对量子热机等器件性能至关重要，并提出通过测辐射热计检测。