Atomic Physics Seminar | Tao Wang, Berkeley | "Ultrahigh Sensitivity Magnetometry and its Applications to Dark Matter Researches" | Jadwin 303

Mon, Jul 29, 2019, 2:00 pm

Dark  matter  and  dark  energy are  the  most  abundant  yet  mysterious  substances  in  the  Universe. Axions  and  axion-like  particles (ALP) have emerged as theoretically well-motivated dark-matter candidates. Ultrahigh sensitivity magnetometers play important roles in dark matter searches. Here we demonstrate a Spin-Exchange Relaxation-Free (SERF) magnetometer/co-magnetometer useful for detecting axion/ALP induced ac-EDMs (electric dipole moment) in ferroelectric samples or ALP induced pseudo-magnetic fields. Even greater sensitivity could be achieved with a ferromagnetic precessing needle magnetometer, whose sensitivity could surpass the standard quantum limit. Levitation of a micron-scale ferromagnetic particle above a superconductor is a possible method of near frictionless suspension enabling observation of ferromagnetic particle precession and ultra-sensitive torque measurements. We experimentally investigate the dynamics of a micron-scale ferromagnetic particle levitated above a superconducting niobium surface.Dark  matter  and  dark  energy are  the  most  abundant  yet  mysterious  substances  in  the  Universe. Axions  and  axion-like  particles (ALP) have emerged as theoretically well-motivated dark-matter candidates. Ultrahigh sensitivity magnetometers play important roles in dark matter searches. Here we demonstrate a Spin-Exchange Relaxation-Free (SERF) magnetometer/co-magnetometer useful for detecting axion/ALP induced ac-EDMs (electric dipole moment) in ferroelectric samples or ALP induced pseudo-magnetic fields. Even greater sensitivity could be achieved with a ferromagnetic precessing needle magnetometer, whose sensitivity could surpass the standard quantum limit. Levitation of a micron-scale ferromagnetic particle above a superconductor is a possible method of near frictionless suspension enabling observation of ferromagnetic particle precession and ultra-sensitive torque measurements. We experimentally investigate the dynamics of a micron-scale ferromagnetic particle levitated above a superconducting niobium surface.

Location: 
Jadwin 303
Speaker(s):