arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2005.07337cond-mat.str-elcond-mat.stat-mechhep-lathep-th
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拓扑相变附近的分形电导率和涌现自对偶性

Fractionalized conductivity and emergent self-duality near topological phase transitions

Yan-Cheng Wang, Meng Cheng, William Witczak-Krempa, Zi Yang Meng

摘要:

二维电子气中分数霍尔电导率的实验发现揭示了新类型的量子粒子,称为任意子,它们超越了玻色子和费米子,因为它们具有分数交换统计。这些任意子通常在绝缘拓扑相的深处进行研究。很自然会问这样的分数化是否可以更广泛地检测到,比如说在从常规相到拓扑相的相变附近。为了回答这个问题,我们研究了一个强相关的量子相变之间的拓扑状态,称为$\mathbb{Z}_2$量子自旋液体,和一个传统的超流体使用大规模的量子蒙特卡罗模拟。我们的结果表明,在量子临界点的普遍电导率成为一个简单的分数,其值在传统的绝缘体超流体的转变。此外,动态自对偶光学电导率出现在低温以上的转变点,表明难以捉摸的视子粒子的存在。我们的研究为在更广泛的范围内实验检测任意子打开了大门,并在量子材料,可编程量子模拟器和超冷原子气体的研究中产生了影响。在后一种情况下,我们讨论了在光晶格使用现有技术的测量的可行性。

英文摘要:

The experimental discovery of the fractional Hall conductivity in two-dimensional electron gases revealed new types of quantum particles, called anyons, which are beyond bosons and fermions as they possess fractionalized exchange statistics. These anyons are usually studied deep inside an insulating topological phase. It is natural to ask whether such fractionalization can be detected more broadly, say near a phase transition from a conventional to a topological phase. To answer this question, we study a strongly correlated quantum phase transition between a topological state, called a $\mathbb{Z}_2$ quantum spin liquid, and a conventional superfluid using large-scale quantum Monte Carlo simulations. Our results show that the universal conductivity at the quantum critical point becomes a simple fraction of its value at the conventional insulator-to-superfluid transition. Moreover, a dynamically self-dual optical conductivity emerges at low temperatures above the transition point, indicating the presence of the elusive vison particles. Our study opens the door for the experimental detection of anyons in a broader regime, and has ramifications in the study of quantum materials, programmable quantum simulators, and ultra-cold atomic gases. In the latter case, we discuss the feasibility of measurements in optical lattices using current techniques.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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