2009/03/07 by Nobutaka Shimizu, Shimizu, Nobutaka, Yoshinori Yasuta +3
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #FOS: Physical sciences #Geophysics and Gravity Measurements #Other Condensed Matter (cond-mat.other) #Quantum, superfluid, helium dynamics #Spacecraft and Cryogenic Technologies #cond-mat.other
paper · pdf · doi:10.48550/arxiv.0903.1326
4 pages, 5 figures
openalex publication_date 2009/03/07 · arxiv created 2009/11/29 · arxiv updated 2009/12/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A detailed torsional oscillator (TO) study on a stable solid 4He sample at 49 bar with To = 0.5K, is reported to T below the dissipation peak at Tp . We find hysteretic behavior starting below Tc = about 75 mK, in period shift, as well as in dissipation, with changes of AC excitation amplitude Vac . The derived difference of non-linear rotational susceptibility DeltaNLRS(T)hys across the hysteresis loop under a systematic condition is analyzed as a function of Vac and T . We propose that DeltaN LRS(T)hys is proportional to non- classical rortational inertia fraction, NCRIF, and is actually the supersolid density rhoss of the 3D supersolid state below Tc . rhoss changes linearly with T down to about 60 mK and then increases much more steeply, and approaching a finite value towards T = 0. We find an AC velocity of 40 micrometer/s beyond which the hysteresis starts at T < Tc and a critical AC velocity, about 1 cm/s, above which rhoss is completely destroyed. We discuss also the coherence length of the supersolid.