Zobrazeno 1 - 10
of 110
pro vyhledávání: '"Shirahama, Keiya"'
We review our study of critical phenomena in superfluid $^4$He confined in nanoporous glasses. $^4$He in nanoporous media is an ideal ground to survey the quantum phase transition of bosons. In the present work, critical phenomena were examined using
Externí odkaz:
http://arxiv.org/abs/2205.08727
$^4$He confined in nanoporous Gelsil glass is a unique, strongly correlated Bose system exhibiting quantum phase transition (QPT) by controlling pressure. Previous studies revealed that the QPT occurs with four - dimensional (4D) XY criticality, whic
Externí odkaz:
http://arxiv.org/abs/2107.07398
Evidence for 4D XY Quantum Criticality in $^4$He Confined in Nanoporous Media at Finite Temperatures
Publikováno v:
Journal of the Physical Society of Japan 90, 033601 (2021)
$^4$He confined in nanoporous media is a model Bose system that exhibits quantum phase transition (QPT) by varying pressure. We have precisely determined the critical exponent of the superfluid density of $^4$He in porous Gelsil glasses with pore siz
Externí odkaz:
http://arxiv.org/abs/2104.05934
Publikováno v:
Phys. Rev. Lett. 123, 245301 (2019)
Molecular hydrogen is a fascinating candidate for quantum fluid showing bosonic and fermionic superfluidity. We have studied diffusion dynamics of thin films of H$_2$, HD and D$_2$ adsorbed on a glass substrate by measurements of elasticity. The elas
Externí odkaz:
http://arxiv.org/abs/1908.06788
Adsorbed molecular films provide two-dimensional systems that show various emergent phenomena that are not observed in bulk counterparts. We have measured the elasticity of thin neon films adsorbed on porous glass down to 1 K by the torsional oscilla
Externí odkaz:
http://arxiv.org/abs/1908.06787
Autor:
Tsuiki, Tomoya, Takahashi, Daisuke, Murakawa, Satoshi, Okuda, Yuichi, Kono, Kimitoshi, Shirahama, Keiya
Publikováno v:
Phys. Rev. B 97, 054516 (2018)
We report measurements of elastic moduli of hcp solid $^4$He down to 15 mK when the samples are rotated unidirectionally. Recent investigations have revealed that the elastic behavior of solid $^4$He is dominated by gliding of dislocations and pinnin
Externí odkaz:
http://arxiv.org/abs/1711.04222
Autor:
Choi, Jaewon, Tsuiki, Tomoya, Takahashi, Daisuke, Choi, Hyoungsoon, Kono, Kimitoshi, Shirahama, Keiya, Kim, Eunseong
Publikováno v:
Phys. Rev. B 98, 014509 (2018)
The irrotational nature of superfluid helium was discovered through its decoupling from the container under rotation. Similarly, the resonant period drop of a torsional oscillator (TO) containing solid helium was first interpreted as the decoupling o
Externí odkaz:
http://arxiv.org/abs/1701.07190
Publikováno v:
Phys. Rev. B 93, 214512 (2016)
We investigate the origin of a resonant period drop of a torsional oscillator (TO) containing solid ${}^{4}$He by inspecting its relation to a change in elastic modulus. To understand this relationship directly, we measure both phenomena simultaneous
Externí odkaz:
http://arxiv.org/abs/1603.07184
Autor:
Shibayama, Yoshiyuki, Shirahama, Keiya
Helium in nanoporous media has attracted much interest as a model Bose system with disorder and confinement. Here we have examined how a change in porous structure by preplating a monolayer of krypton affects the superfluid properties of $^4$He adsor
Externí odkaz:
http://arxiv.org/abs/1105.4346
Publikováno v:
Physical Review Letters 105, 236103 (2010)
We report measurements of noncontact friction between surfaces of NbSe$_{2}$ and SrTiO$_{3}$, and a sharp Pt-Ir tip that is oscillated laterally by a quartz tuning fork cantilever. At 4.2 K, the friction coefficients on both the metallic and insulati
Externí odkaz:
http://arxiv.org/abs/1012.2434