The Mott insulator and superfluid phase transition is one of the most prominent phenomena in ultracold atoms.We report the observation of a novel 2D quantum phase transition between the Mott insulator andπsuperfluid ...The Mott insulator and superfluid phase transition is one of the most prominent phenomena in ultracold atoms.We report the observation of a novel 2D quantum phase transition between the Mott insulator andπsuperfluid in a shaking optical lattice.In the deep optical lattice regime,the lowest S band can be tuned to Mott phase,while the higher P_(x,y)bands are itinerant for having larger bandwidth.Through a shaking technique coupling the s-orbital to p_(x,y)-orbital states,we experimentally observe the transition between the states of the S and P_(x,y)bands,leading to a quantum phase transition from two-dimensional s-orbital Mott phase to the p_(x,y)-orbital superfluid which condensed at(π,π)momentum.Using the band-mapping method,we also observe the changes of atomic population in different energy bands during the transition,and the experimental results are well consistent with theoretical expectations.展开更多
基金supported by the National Natural Science Foundation of China (21872116)the Mobility Program of the SinoGerman Center for research Promotion (M-0377)China Scholarship Council。
文摘硫化锑铜(CuSbS_(2))是一种p型半导体,带隙为1.5 eV,同时拥有较大的光吸收系数(>105cm-1),因此在光电催化领域拥有广阔的应用前景.但是目前国内外的研究还缺乏对CuSbS_(2)电子结构以及其如何影响PEC性能的深入理解.为了进一步改善CuSbS_(2)的PEC性能,对其电子结构进行一系列表征分析是非常重要的.本文中,我们利用同步辐射技术揭示了CuSbS_(2)的电子结构.结果表明,CuSbS_(2)的价带(VB)由S 3p和Cu 3d的强杂交态组成,同时Sb 5p/5s也有部分影响.基于以上理论指导,我们设计了一种高质量Cu Sb S_(2)薄膜的制备技术,并使用FTO/CuSbS_(2)/CdS/Pt光电阴极在0.0 V下实现了CuSbS_(2)基材料的高光电流密度(6.3 mA cm^(-2)).
基金supported by the National Natural Science Foundation of China(Grant Nos.11920101004,11934002)the National Key Research and Development Program of China(Grant Nos.2021YFA1400900,2021YFA0718300)。
文摘The Mott insulator and superfluid phase transition is one of the most prominent phenomena in ultracold atoms.We report the observation of a novel 2D quantum phase transition between the Mott insulator andπsuperfluid in a shaking optical lattice.In the deep optical lattice regime,the lowest S band can be tuned to Mott phase,while the higher P_(x,y)bands are itinerant for having larger bandwidth.Through a shaking technique coupling the s-orbital to p_(x,y)-orbital states,we experimentally observe the transition between the states of the S and P_(x,y)bands,leading to a quantum phase transition from two-dimensional s-orbital Mott phase to the p_(x,y)-orbital superfluid which condensed at(π,π)momentum.Using the band-mapping method,we also observe the changes of atomic population in different energy bands during the transition,and the experimental results are well consistent with theoretical expectations.
