Hole-spin mixing in InAs quantum dot molecules
Hole-spin mixing in InAs quantum dot molecules
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DOI：
10.1103/physrevb.81.035308
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发表时间：
2010-01-01
影响因子：
3.7
通讯作者：
Gammon, D.
中科院分区：
文献类型：
--
作者：
Doty, M. F.;Climente, J. I.;Gammon, D.
限制在单个 InAs 量子点中的空穴自旋态最近已成为用于存储或操纵量子信息的有前景的系统。通常假设这些空穴在正交重空穴自旋投影之间没有混合（在没有横向磁场的情况下）。同样的假设也适用于由两个堆叠的 InAs 量子点形成的 InAs 量子点分子，这两个量子点通过两个点之间空穴的相干隧道耦合。我们提出了通过磁光致发光光谱在此类 InAs 量子点分子上获得的空穴自旋混合项存在的实验证据。我们使用 Luttinger 旋量模型来解释空穴自旋混合项的物理起源：点沿堆叠方向的未对准打破了角对称性，并允许重空穴分量通过旋量的轻空穴分量进行混合。我们讨论这种自旋混合机制如何提供空穴特有的新自旋操纵机会。
The spin state of holes confined in single InAs quantum dots have recently emerged as a promising system for the storage or manipulation of quantum information. These holes are often assumed to have no mixing between orthogonal heavy-hole-spin projections (in the absence of a transverse magnetic field). The same assumption has been applied to InAs quantum dot molecules formed by two stacked InAs quantum dots that are coupled by coherent tunneling of the hole between the two dots. We present experimental evidence of the existence of a hole-spin-mixing term obtained with magnetophotoluminescence spectroscopy on such InAs quantum dot molecules. We use a Luttinger spinor model to explain the physical origin of this hole-spin-mixing term: misalignment of the dots along the stacking direction breaks the angular symmetry and allows mixing of the heavy-hole components through the light-hole component of the spinor. We discuss how this spin-mixing mechanism may offer new spin manipulation opportunities that are unique to holes.