2021

Yaoming Chu, Shaoliang Zhang, Baiyi Yu, and Jianming Cai, Phys. Rev. Lett. 126, 010502 (2021)

We propose a dynamic framework for quantum sensing with a family of Hamiltonians that undergo quantum phase transitions (QPTs). By giving the formalism of the quantum Fisher information (QFI) for quantum sensing based on critical quantum dynamics, we demonstrate its divergent feature when approaching the critical point.

Min Yu, Dongxiao Li, Jingcheng Wang, Yaoming Chu, Pengcheng Yang, Musang Gong, Nathan Goldman, Jianming Cai, Phys. Rev. Research 3, 043122 (2021)

Our results highlight the general applicability of our method to general quantum platforms, including solid-state spin systems, superconducting quantum computers and trapped ions, hence providing a versatile tool to explore the essential role of the QFI in quantum physics.

Ralf Betzholz, Yu Liu, and Jianming Cai, Phys. Rev. A 104, 012421 (2021)

We present a method for the direct measurement of the Wigner characteristic function of a thermalizing harmonic oscillator that is completely inaccessible for control or measurement.

Yaoming Chu, Pengcheng Yang, Musang Gong, Min Yu, Baiyi Yu, Martin B. Plenio, Alex Retzker, and Jianming Cai, Phys. Rev. Applied 15, 014031 (2021).

By invoking a stable classical clock, the signal phase correlations between successive measurements enable us to extract the target frequency with extremely high precision.