EQuAL Seminar: Oleksii Laguta

Electron Paramagnetic Resonance Imaging with (sub)THz Microwaves

Magnetic resonance imaging has its primary usage in medical diagnosis and life science, and it is rarely performed with radio frequencies above 1 GHz due to the strong absorption of electromagnetic waves in tissue. Solid state materials though are mostly transparent to radio- and microwaves, and therefore, going to higher frequencies, e.g. up to terahertz range, is promising. Doing so has three advantages: (i) higher sensitivity due to a larger population difference among spin levels, (ii) higher spectral resolution, and (iii) the ability to study high spin systems with large zero-field splitting. This will permit three-dimensional visualization of paramagnetic impurities, and given strong enough magnetic field gradients, provide a means to address spin qubits individually via EPR spectroscopy. Additionally, spectral-spatial imaging, combined with resolved magnetic anisotropy, will offer valuable insights into the nature of paramagnetic centers. In this talk, I will present our proof-of-concept implementation of an EPR imaging system operating at microwave frequencies above 100 GHz and magnetic fields up to 16 T. I will also discuss ways of improving it and future perspectives.