Extended Data Fig. 9: Hysteresis on T-sweeps in S2.
From: Imaging the Meissner effect in hydride superconductors using quantum sensors
To study hysteresis on sweeping T, we first zero field cool the sample and apply an external field Hz [maintext Fig. 5(d)]. Then, fixing Hz, we heat the sample across the transition (field heating shown in red). Finally, we cool the sample below Tc without changing Hz (field cooling shown in blue). We perform simultaneous electrical resistance (shown in green) and ODMR measurements. Four point resistance measured on field heating (field cooling) are indicated by markers pointing right (left). All measurements are made at the spatial location shown by the inverted white triangle in fluorescence scan [inset of (d)]. We use the 2Π⊥ stress parameter measured at Hz = 0 and T = 81 K to extract the local Bz field for all data points. (a-c) We observe concurrent transitions in magnetism and electrical resistance. In addition, we see a suppression of Tc with the increase in the magnitude of Hz. (d) Surprisingly at high fields (Hz = 206 G), we see a clear sharpening of the magnetic transition. To confirm the signal we repeat the measurement on field heating near the transition region (orange squares in (d)).
