Seminar Announcement: Tao Wang

Data pubblicazione: 18-giu-2024

Announcement

Thursday, 20 June 2024, 14:30

Sala Grande Palazzina C via alla Cascata 56/C

"Ultrahigh precision magnetometry towards the beyond-the-standard-quantum-limit sensitivity"

Tao Wang

Institute of Materials Research and Engineering (IMRE) - A*STAR

Singapore

E-mail: tao_wang@imre.a-star.edu.sg

Abstract

The vapor cell atomic magnetometers demonstrated the highest magnetic field measurement sensitivity. However, the conventional approaches have limitations in dynamic range or cannot extract three-axis magnetic fields simultaneously, which limit their applications in magnetic anomaly detection and biomedical imaging in the Earth's field. Atomic magnetometers are intrinsically scalar devices that measure the energy splitting between spin states in a magnetic field. A vector magnetometer based on a pulsed RB-87 scalar magnetometer and a fast-rotating magnetic field modulation is achieved. This vector magnetometer provides simultaneous measurements of the total field and two polar angles defining the magnetic field vector while maintaining ultrahigh precision. The systematic effects associated with the rotating field vector magnetometer operation are studied to further improve the magnetometer's accuracy. Furthermore, creating an "artificial atom" at a mesoscopic scale by superconducting levitation can be used for developing next-generation quantum sensors. Under conditions where the angular momentum of a ferromagnetic needle is dominated by intrinsic spin, an applied torque is predicted to cause gyroscopic precession of the needle. If the needle can be sufficiently isolated from the environment, a measurement of the precession can yield sensitivity to torques far beyond that of other systems (such as atomic magnetometers). The high sensitivity results from the rapid averaging of quantum noise.