TY - JOUR
T1 - 4He in nano-porous media
T2 - Superfluidity and quantum phase transition
AU - Shirahama, Keiya
N1 - Funding Information:
I am grateful to my collaborators, Keiichi Yamamoto, Haruki Naka-shima, Yoshihiro Sogabe, and Yoshiyuki Shibayama for the torsional oscillator and pressure studies, and Toshi Kobayashi, Satoru Fukazawa, Junko Taniguchi and Masaru Suzuki for the ultrasound experiment. Thanks are also due to Michikazu Kobayashi and Makoto Tsubota for fruitful discussions. This work is supported by a Grant-in-Aid for Scientific Research (A) and for Priority Area from the Ministry of Science and Education, Japan. Last but not least, I would like to thank Professor Frank Pobell for his leadership and effort of many years in the field of low temperature physics. Although I was a “disciple unworthy of him”, I learned much about low temperature physics during my stay in Bayreuth, and they have been essential in my research work.
PY - 2007/3
Y1 - 2007/3
N2 - This paper reviews recent findings of novel phenomena in 4He confined to a nano-porous glass. We examined pressure-temperature (P-T) phase diagram of 4He confined in a porous Gelsil glass that had nanopores 2.5 nm in diameter, by torsional oscillator and pressure studies. The obtained phase diagram is fairly unprecedented: the superfluid transition temperature approaches zero at 3.4 MPa, and a novel nonsuperfluid phase exists between the superfluid and solid phase. These observations indicate that the confined 4He undergoes a superfluid-nonsuperfluid-solid quantum phase transition at zero temperature. We propose that the nonsuperfluid phase may be a localized Bose-condensed state in which global phase coherence is destroyed by a strong correlation between the 4He atoms or by a random potential. 4He in nanospace is an excellent model system for studying a strongly correlated Bose liquid and solid in a confinement potential.
AB - This paper reviews recent findings of novel phenomena in 4He confined to a nano-porous glass. We examined pressure-temperature (P-T) phase diagram of 4He confined in a porous Gelsil glass that had nanopores 2.5 nm in diameter, by torsional oscillator and pressure studies. The obtained phase diagram is fairly unprecedented: the superfluid transition temperature approaches zero at 3.4 MPa, and a novel nonsuperfluid phase exists between the superfluid and solid phase. These observations indicate that the confined 4He undergoes a superfluid-nonsuperfluid-solid quantum phase transition at zero temperature. We propose that the nonsuperfluid phase may be a localized Bose-condensed state in which global phase coherence is destroyed by a strong correlation between the 4He atoms or by a random potential. 4He in nanospace is an excellent model system for studying a strongly correlated Bose liquid and solid in a confinement potential.
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U2 - 10.1007/s10909-006-9277-6
DO - 10.1007/s10909-006-9277-6
M3 - Review article
AN - SCOPUS:33847075475
SN - 0022-2291
VL - 146
SP - 485
EP - 497
JO - Journal of Low Temperature Physics
JF - Journal of Low Temperature Physics
IS - 5-6
ER -