Quantum phase transitions and non-equilibrium dynamics of disordered one-dimensional quantum fluids

2015 Fiscal Year Final Research Report

• Project/Area Number: 25800228
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Atomic/Molecular/Quantum electronics
• Research Institution: Kyoto University
• Principal Investigator: Danshita Ippei 京都大学, 基礎物理学研究所, 助教 (90586950)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 冷却気体 / 光格子 / 超流動 / 量子相転移

Outline of Final Research Achievements

We have studied the effects of impurities on properties of ultracold quantum gases, such as quantum phase transitions. Our main focus has been placed on single-component and two-component Bose gases, which are precisely controllable in experiments. We have successfully resolved some long-standing problems and found novel phenomena. Specifically, we have proposed a way to experimentally quantify the breakdown of superfluid flow due to quantum phase slips in a system of one-dimensional single-component Bose gases. As for two-component Bose gases in optical lattices, we have found surface critical phenomena caused by impurity potential. Moreover, we consider a relativistic superfluid of single-component Bose gases in optical lattices to predict the existence of a novel elementary excitation, namely the Higgs bound state.

Free Research Field

凝縮系理論