Creating a supersolid in one-dimensional Bose mixtures
Creating a supersolid in one-dimensional Bose mixtures
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DOI：
10.1103/physreva.79.011602
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发表时间：
2008-06
影响因子：
2.9
通讯作者：
L. Mathey;I. Danshita;C. Clark
中科院分区：
文献类型：
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作者：
L. Mathey;I. Danshita;C. Clark
我们确定了一个一维的超固相在二元混合物的近硬核玻色子弱，当地种间排斥。我们发现现实的条件下，这样的阶段，这里定义为准超流性和准电荷密度波序的共存，可以产生和观察到在有限的超冷原子系统中的谐波陷阱。我们的分析基于Luttinger液体理论，并使用时间演变块抽取方法进行数值计算。在飞行时间干涉图和从密度相关性导出的结构因子S（k）中，可以分别找到这两个阶数的清晰实验特征。足够弱。我们研究了SS相的分析和数值技术，并提出了一个具体的建议，其真实的- ization在目前的实验系统。首先，我们用Luttinger液体（LL）方法导出均匀无限大体系的相图，并进行重整化群（RG）计算。然后，我们解决的问题，实现这样的一个阶段在现实的条件下，为一个有限系统的102个晶格位置的谐波陷阱。使用数量守恒的时间演化块抽取（TEBD）方法（15），我们以良好控制的误差数值地确定系统的基态，我们从该基态提取各种相关函数。我们首先确定的SS阶段，通过在对和反对相关的signa- tures。其他关联包含的信息可以直接通过实验观察得到，我们讨论了SS相的可能实验特征，即SF和CDW序的共存，SF序表现在单粒子关联函数中，它可以通过飞行时间（TOF）干涉图确定;密度-密度相关性中可以看到CDW有序性，这反映在可测量的结构因子中。我们考虑了两种玻色子原子的混合物，它们具有短程粒子间相互作用，被限制在一维光学晶格和一个附加的谐波势中。当代实验实现的这类系统通常很好地近似于哈伯德模型：
We identify a one-dimensional supersolid phase in a binary mixture of near-hardcore bosons with weak, local interspecies repulsion. We find realistic conditions under which such a phase, defined here as the coexistence of quasi-superfluidity and quasi-charge density wave order, can be produced and observed in finite ultra-cold atom systems in a harmonic trap. Our analysis is based on Luttinger liquid theory supported with numerical calculations using the time-evolving block decimation method. Clear experimental signatures of these two orders can be found, respectively, in time-of-flight interference patterns, and the structure factor S(k) derived from density correlations. sufficiently weak. We study the SS phase with analytical and numerical techniques, and present a concrete proposal for its real- ization in current experimental systems. First we use a Luttinger liquid (LL) approach to derive the phase dia- gram of the homogeneous, infinite system, with a renor- malization group (RG) calculation. We then address the question of realizing such a phase under realistic condi- tions, for a finite system of ∼ 10 2 lattice sites in a har- monic trap. Using a number-conserving time-evolving block decimation (TEBD) method (15) we numerically determine, with a well-controlled error, the ground state of the system from which we extract various correlation functions. We first identify the SS phase, through signa- tures in the pair and anti-pair correlations. Other cor- relations contain information that is accessible to direct experimental observation, and we discuss possible exper- imental signatures of the SS phase, i.e. the coexistence of SF and CDW order; the SF order is manifest in the single-particle correlation function, which can be deter- mined from time-of-flight (TOF) interference patterns; the CDW order is seen in density-density correlations, which is reflected in a measurable structure factor. We consider a mixture of two species of bosonic atoms with short-range interparticle interactions, confined in a 1D optical lattice and an additional harmonic potential. Contemporary experimental realizations of such systems are usually well approximated by a Hubbard model: