Dynamic Cooling with Contemporary Quantum Computers

Quantum computers require qubits to be initialized in a pure (i.e., cold) state in order to run properly. Dynamic cooling offers a route for effectively lowering qubit temperatures beyond what is possible with direct, physical cooling methods. It works by cooling a subset of qubits, at the expense of heating others, by applying certain logic gates to the entire system. While it was initially dismissed as impractical for the high-temperature NMR-based quantum computers available at the time of its inception, we show how dynamic cooling is substantially more effective and efficient on the low-temperature quantum computers available today. We explore optimal dynamic cooling in terms of the final temperature of the cooled sub-system, the work cost, and the complexity of the associated quantum circuits. Finally, we examine the effect of hardware noise on cooling and conclude that dynamic cooling is a promising technique for near-future quantum computers with reduced levels of noise.

Seminar realized in the framework of the funded project:
QC4QT, Marie Skłodowska-Curie grant agreement- GA No 101063316.