No expert by any means, but SQUIDs[1] rely on superconductivity to detect tiny magnetic fields. One use is for recording neuron activity[2], so perhaps room-temperature superconductors could allow for a portable setup.
This article[3] goes into some of the advantages of a less restrictive setup, but the laser-pumped sensors they rely on still require a lot of additional hardware.
This article[3] goes into some of the advantages of a less restrictive setup, but the laser-pumped sensors they rely on still require a lot of additional hardware.
[1]: https://en.wikipedia.org/wiki/SQUID
[2]: https://en.wikipedia.org/wiki/Magnetoencephalography
[3]: https://hebergement.universite-paris-saclay.fr/supraconducti...