报告时间：2017年3月28日下午16：00

报告地点：近代物理系210会议室

报告人：慕尼黑工业大学的Friedemann Reinhard研究员

报告题目：“Quantum sensing of weak GHz frequency fields – towards a microwave single photon detector?”

欢迎感兴趣的同学前来参加！

摘要：Solid state qubits, such as the Nitrogen-Vacancy (NV) center in diamond, have become powerful sensors for nanoscale magnetic and electric fields. A major key for their success have been dynamical decoupling protocols, which strongly amplify tiny AC signals. Currently, those methods are limited to signal frequencies up to several MHz.

Here, we present a novel DD protocol specifically designed to detect weak fields close to the NV's transition frequency (~2 GHz).  It is based on a quantum-optical effect, the Mollow triplet splitting of a strongly driven two-level system. We microscopically understand this effect as a pulsed dynamical decoupling protocol and find that it enables sensitive detection of fields close to the driven transition.

Employing a nitrogen-vacancy center, we detect GHz microwave fields with a signal strength (Rabi frequency) below the current detection limit, which is set by the center’s spectral linewidth 1/T2*.

I will speculate on possible applications, in particular spin-phonon coupling and detection of single microwave photons in superconducting circuits.