TY - JOUR
T1 - Anomalous response of 4He confined in nanoporous media to torsional oscillation
AU - Yoshimura, Hitomi
AU - Higashino, Rama
AU - Shibayama, Yoshiyuki
AU - Shirahama, Keiya
N1 - Funding Information:
Acknowledgements We are grateful to M. Kondo and S. Takada for early stage of the experiment. This work is supported by Grant-in-Aid for Scientific Research (S) titled “Nano-scale Helium Physics and its Applications” by JSPS, and Grant-in-Aid for Scientific Research in Priority Area “Physics of Superclean Materials” by MEXT, Japan.
PY - 2012/11
Y1 - 2012/11
N2 - The existence of "Non-Classical Rotational Inertia (NCRI)" in solid 4He below 0.2 K has been controversial and interpreted by a number of different theories. We report on torsional oscillator measurements for 4He in a nanoporous Gelsil glass, which has a network of nanopores with 3.5 nm in diameter. In addition to the usual "low-T NCRI" with an onset temperature 0.15 K, we find a larger decrease in rotational moment of inertia in a broad range of temperature from 0.2 to 1.9 K. This "high-T inertial anomaly" is accompanied with multiple dissipation peaks, but has no dependence on torsional oscillation velocity unlike the low-T NCRI. Since the high-T anomaly is observed also in confined liquid states, it originates in amorphous solid 4He layer near the pore wall. Our result shows that different types of supersolid - like phenomena, i.e. inertial anomalies, can coexist in a single 4He sample, even with genuine superfluidity of liquid 4He.
AB - The existence of "Non-Classical Rotational Inertia (NCRI)" in solid 4He below 0.2 K has been controversial and interpreted by a number of different theories. We report on torsional oscillator measurements for 4He in a nanoporous Gelsil glass, which has a network of nanopores with 3.5 nm in diameter. In addition to the usual "low-T NCRI" with an onset temperature 0.15 K, we find a larger decrease in rotational moment of inertia in a broad range of temperature from 0.2 to 1.9 K. This "high-T inertial anomaly" is accompanied with multiple dissipation peaks, but has no dependence on torsional oscillation velocity unlike the low-T NCRI. Since the high-T anomaly is observed also in confined liquid states, it originates in amorphous solid 4He layer near the pore wall. Our result shows that different types of supersolid - like phenomena, i.e. inertial anomalies, can coexist in a single 4He sample, even with genuine superfluidity of liquid 4He.
KW - Helium
KW - Supersolid
UR - http://www.scopus.com/inward/record.url?scp=84867233297&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84867233297&partnerID=8YFLogxK
U2 - 10.1007/s10909-012-0687-3
DO - 10.1007/s10909-012-0687-3
M3 - Article
AN - SCOPUS:84867233297
SN - 0022-2291
VL - 169
SP - 218
EP - 227
JO - Journal of Low Temperature Physics
JF - Journal of Low Temperature Physics
IS - 3-4
ER -