Optimally Fast Qubit Reset

TL;DR

This paper develops a framework for minimal thermodynamic cost and optimal protocols for qubit reset at various speeds, revealing fundamental trade-offs and optimal conditions for different bath types.

Contribution

It introduces a general method to determine the minimal thermodynamic cost and optimal reset protocols for arbitrary speeds, accounting for different bath types and convergence behaviors.

Findings

Divergent entropy production depends on jump operator behavior.

Trade-off between reset time and error probability in convergent cases.

Super-Ohmic bosonic baths are optimal for qubit reset.

Abstract

In practice, qubit reset must be operated in an extremely short time, which incurs a thermodynamic cost within multiple orders of magnitude above the Landauer bound. We present a general framework to determine the minimal thermodynamic cost and the optimal protocol for arbitrary resetting speeds. Our study reveals the divergent behavior of minimal entropy production in the short-time limit depends on the convergence and divergence of the jump operators. For the convergent class, an inherent trade-off exists between the minimal required time and the set error probability, which hinders the Moore's law continuing in such cases. Moreover, we find the optimal protocol exhibits the similarity in the fast-driving regime for different times. To demonstrate our findings, we empoly fermionic and bosonic baths as examples. Our results suggest that the super-Ohmic bosonic heat bath is a suitable choice for qubit reset.