Highly Sensitive Detection of Pulsed Field ESR Using a Cantilever at Low Temperature

We have succeeded in observing the high field ESR of 800 ng Co‐Tutton salt at 1.7 K in the millimeter wave region, using a cantilever and a pulsed magnetic field. This is a new high‐sensitivity ESR detection technique at low temperature in a pulsed magnetic field, with a sensitivity 10⁴ times higher than that of the conventional transmission technique. Possible application to the terahertz ESR is discussed.