QF Fellow and Associate seminar: Alex Giovannone

Free Electron Laser Powered Electron Spin Resonance 

Alex is a graduate student in the Sherwin Group and will be sharing his work with Electron Spin Resonance (ESR). ESR is a powerful tool for probing spin dynamics in quantum materials, molecules, and magnetic systems. To study systems with nanosecond spin relaxation times at very high frequencies and magnetic fields, we are developing a unique pulsed ESR spectrometer at UCSB. The instrument operates from 170-420 GHz, up to 16 T, and at temperatures ranging from 2-300 K. It uses both amplifier-multiplier chains and one of UCSB's free-electron lasers (FELs) as microwave sources. The FEL can deliver kilowatt-level pulses, which we shape into precisely controlled microwave bursts using custom-built pulse slicers and phase shifters. A quasi-optical circuit allows flexible operation in continuous-wave, pulsed, and two-color pump-probe modes. This system will enable new experiments on fast spin relaxation, spectral-hole burning, and other spin-dependent phenomena at high frequencies and fields.