Approaching the Limit of Quantum Clock Precision

TL;DR

This paper proposes a quantum clock design using time-independent interactions and dissipative spin chains, achieving near-optimal precision and robustness through a novel sudden-quench protocol.

Contribution

It introduces a blueprint for a quantum clock with optimal precision scaling and a robust repeated-operation protocol, advancing practical quantum timekeeping.

Findings

Achieves precision-resolution trade-off at fundamental bound

Develops a robust sudden-quench protocol for repeated operation

Demonstrates high-precision timekeeping with lower-precision drives

Abstract

Precise and autonomous clocks are of fundamental interest and central importance to both foundational studies and practical applications. Here, we construct a blueprint for a quantum clock governed by time-independent interactions. By carefully-engineered coherent transport in dissipative spin chains, we achieve a scaling exponent at the precision-resolution trade-off fundamental bound, bringing this within reach of physically realistic and experimentally accessible systems. We further introduce a sudden-quench protocol that enables repeated operation through a simple initialization and detachment mechanism. Remarkably, the protocol is robust to imprecise detachment timing, implying that high-precision timekeeping can be achieved even when driven by a clock with much lower precision.