Localization of Bose-Einstein Condensation and Disappearance of Superfluidity of Strongly Correlated Bose Fluid in a Confined Potential

We develop a Bose fluid model in a confined potential to consider the new quantum phase due to the localization of Bose-Einstein condensation and disappearance of superfluidity which is recently observed in liquid 4He in porous glass at high pressures. A critical pressure of the transition to this phase can be defined by our new analytical criterion of supposing the size of localized Bose-Einstein condensate becomes comparable to the scale of confinement. The critical pressure is quantitatively consistent with observations without free parameters.Comment: 2 pages, 1 figur

ウェーブレットに基づいた地中レーダ受信信号のノイズ除去と埋設管位置標定に関する研究

電気通信大学201

Quantized vortices in superfluid helium and atomic Bose-Einstein condensates

This article reviews recent developments in the physics of quantized vortices in superfluid helium and atomic Bose-Einstein condensates. Quantized vortices appear in low-temperature quantum condensed systems as the direct product of Bose-Einstein condensation. Quantized vortices were first discovered in superfluid 4He in the 1950s, and have since been studied with a primary focus on the quantum hydrodynamics of this system. Since the discovery of superfluid 3He in 1972, quantized vortices characteristic of the anisotropic superfluid have been studied theoretically and observed experimentally using rotating cryostats. The realization of atomic Bose-Einstein condensation in 1995 has opened new possibilities, because it became possible to control and directly visualize condensates and quantized vortices. Historically, many ideas developed in superfluid 4He and 3He have been imported to the field of cold atoms and utilized effectively. Here, we review and summarize our current understanding of quantized vortices, bridging superfluid helium and atomic Bose-Einstein condensates. This review article begins with a basic introduction, which is followed by discussion of modern topics such as quantum turbulence and vortices in unusual cold atom condensates.Comment: 99 pages, 20 figures, Review articl