Quantum Optics Seminar: Lauri Parkkonen, Aalto University

Quantum sensing for measuring brain function

Electrical signalling in cerebral neurons gives rise to weak but measurable magnetic fields outside of the human head. Inferring brain function by measuring these fields is referred to as magnetoencephalography (MEG). These femtotesla-level fields are conventionally recorded with superconducting quantum interference devices (SQUIDs). However, the cryogenic temperatures required by SQUIDs hamper their application to MEG. Recently, optically pumped magnetometers (OPMs) have attained sufficient sensitivity for recording MEG signals. OPMs can be placed closer to the head than SQUIDs, thereby increasing spatial resolution.

In this talk, I will cover the signal generation in MEG, compare the two quantum sensor types in the MEG application, describe the required instrumentation to perform MEG, and highlight our recent neuroscientific findings using these sensors.