arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0903.3108cond-mat.mes-hallcond-mat.str-el
收藏

非阿贝尔干涉仪

The non-Abelian Interferometer

Waheb Bishara, Parsa Bonderson, Chetan Nayak, Kirill Shtengel, J. K. Slingerland

摘要:

我们认为隧道电流通过一个双点接触法布里-珀罗干涉仪,如在最近的实验研究中使用的分数量子霍尔坪填充分数为5/2。我们比较了几种不同的电子态模型的预言:Moore-Read,anti-Pfiran,SU(2)_2NAF,K=8强配对,和(3,3,1)态。所有这些都预言了荷e/4准粒子的存在,但前三个是非阿贝尔的,后两个是阿贝尔的。我们给出了明确的公式缩放的电荷e/2和电荷e/4准粒子的贡献,电流作为温度,栅极电压和两个点之间的距离接触的函数为所有三个模型。在此基础上,我们分析了Willett等人最近实验中报告的两种现象的几种可能解释,即随着温度的升高,所观察到的电阻振荡的周期减半,并且在低温下,当干扰环的面积随着侧门而变化时,在相同的两个所观察到的周期之间交替。我们的结论是,最可能的解释是,观察到的交替是由于偶数和奇数之间的切换作为侧栅电压的函数,这是一个明确的签名的存在下,非阿贝尔任意子的电荷e/4准粒子封闭在循环。然而,在这幅图中,数据的一些重要特征并没有得到简单的解释。我们建议进一步的实验,可以帮助排除一些可能的情况。我们对未来在其它观测到的第二朗道能级分数量子霍尔态上的隧穿和干涉实验做了相应的预测。

英文摘要:

We consider the tunneling current through a double point-contact Fabry-Perot interferometer such as used in recent experimental studies of the fractional quantum Hall plateau at filling fraction nu=5/2. We compare the predictions of several different models of the state of the electrons at this plateau: the Moore-Read, anti-Pfaffian, SU(2)_2 NAF, K=8 strong pairing, and (3,3,1) states. All of these predict the existence of charge e/4 quasiparticles, but the first three are non-Abelian while the last two are Abelian. We give explicit formulas for the scaling of charge e/2 and charge e/4 quasiparticle contributions to the current as a function of temperature, gate voltage and distance between the two point contacts for all three models. Based on these, we analyze several possible explanations of two phenomena reported for recent experiments by Willett et al., namely halving of the period of the observed resistance oscillations with rising temperature and alternation between the same two observed periods at low temperatures as the area of the interference loop is varied with a side gate. We conclude that the most likely explanation is that the observed alternation is due to switching between even and odd numbers of charge e/4 quasiparticles enclosed within the loop as a function of side gate voltage, which is a clear signature of the presence of non-Abelian anyons. However, there are important features of the data which do not have a simple explanation within this picture. We suggest further experiments which could help rule out some possible scenarios. We make the corresponding predictions for future tunneling and interference experiments at the other observed second Landau level fractional quantum Hall states.

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。

↑