Mintairov Alexander M, Lebedev Dmitrii V, Vlasov Alexey S, Blundell Steven A
Ioffe Institute, 194021 Saint Petersburg, Russia.
Electrical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
Nanomaterials (Basel). 2022 Mar 20;12(6):1016. doi: 10.3390/nano12061016.
In magneto-photoluminescence (magneto-PL) spectra of quasi two-dimensional islands (quantum dots) having seven electrons and Wigner−Seitz radius rs1.5, we revealed a suppression of magnetic field (B) dispersion, paramagnetic shifts, and jumps of the energy of the emission components for filling factors ν > 1 (B < 10 T). Additionally, we observed B-hysteresis of the jumps and a dependence of all these anomalous features on rs. Using a theoretical description of the magneto-PL spectra and an analysis of the electronic structure of these dots based on the single-particle Fock−Darwin spectrum and many-particle configuration-interaction calculations, we show that these observations can be described by the rs-dependent formation of the anyon (magneto-electron) composites (ACs) involving single-particle states having non-zero angular momentum and that the anyon states observed involve Majorana modes (MMs), including zero-B modes having an equal number of vortexes and anti-vortexes, which can be considered as Majorana anyons. We show that the paramagnetic shift corresponds to a destruction of the equilibrium self-formed ν5/2 AC by the external magnetic field and that the jumps and their hysteresis can be described in terms of Majorana qubit states controlled by B and rs. Our results show a critical role of quantum confinement in the formation of magneto-electrons and implies the liquid-crystal nature of fractional quantum Hall effect states, the Majorana anyon origin of the states having even ν, i.e., composite fermions, which provide new opportunities for topological quantum computing.
在具有七个电子且维格纳-赛茨半径(r_s\approx1.5)的准二维岛（量子点）的磁光致发光（磁光致发光）光谱中，我们发现对于填充因子(\nu>1)（(B<10T)），磁场（(B)）色散、顺磁位移以及发射分量能量的跳跃受到抑制。此外，我们观察到跳跃的(B)滞后现象以及所有这些异常特征对(r_s)的依赖性。通过对磁光致发光光谱的理论描述以及基于单粒子福克-达尔文光谱和多粒子组态相互作用计算对这些量子点电子结构的分析，我们表明这些观测结果可以用依赖于(r_s)的任意子（磁电子）复合体（ACs）的形成来描述，该复合体涉及具有非零角动量的单粒子态，并且所观察到的任意子态涉及马约拉纳模式（MMs），包括具有相等数量涡旋和反涡旋的零(B)模式，其可被视为马约拉纳任意子。我们表明顺磁位移对应于外部磁场对平衡自形成的(\nu\approx5/2)AC的破坏，并且跳跃及其滞后现象可以用由(B)和(r_s)控制的马约拉纳量子比特态来描述。我们的结果表明量子限制在磁电子形成中的关键作用，并暗示了分数量子霍尔效应态的液晶性质、具有偶数(\nu)的态即复合费米子的马约拉纳任意子起源，这为拓扑量子计算提供了新的机会。
