Dataset Associated with 'Deconvolution of Rashba and Dresselhaus spin-orbit coupling by crystal axis dependent measurements of coupled InAs/GaSb quantum wells'

The Dresselhaus spin-orbit interaction is expected to perturb the quantum spin Hall phase predicted to arise within InAs/GaSb coupled quantum wells. To gain a greater understanding of this interaction, the spin-orbit coupling in two InAs/GaSb coupled quantum well samples, grown along the [001] axis, was investigated along three different in-plane crystallographic axes. By measuring the crystallographic axis dependence of the Dresselhaus spin orbit coupling, we can deconvolute this coupling from the spin splitting arising from axis-invariant Rashba spin-orbit coupling. We find that the Dresselhaus parameter is robust against an external gate bias and small changes in growth conditions, with an associated Dresselhaus parameter of (0.20±0.08)×10^-11 eVm being measured across all samples and top gate bias conditions. In addition, we show that the asymmetries associated with the coupled quantum well structure, leading to Rashba spin-orbit coupling, are likely to play a dominant role in determining the spin-orbit interaction experienced by a quantum spin Hall state as the system is tuned towards charge neutrality.人们预期，Dresselhaus自旋轨道相互作用（Dresselhaus spin-orbit interaction）会对InAs/GaSb耦合量子阱中预言存在的量子自旋霍尔相产生扰动。为了更深入地理解该相互作用，我们针对沿[001]轴外延生长的两块InAs/GaSb耦合量子阱样品，沿三种不同的面内晶轴研究了其自旋轨道耦合特性。通过测量Dresselhaus自旋轨道相互作用的晶轴依赖关系，我们可以将该耦合与由轴无关Rashba自旋轨道耦合（Rashba spin-orbit coupling）产生的自旋劈裂分离开来。研究发现，Dresselhaus参数不受外部门电压偏置以及生长条件小幅变化的影响，在所有样品以及顶部门电压偏置条件下测得的Dresselhaus参数为(0.20±0.08)×10^-11 eV·m。此外，我们还发现，耦合量子阱结构带来的不对称性会引发Rashba自旋轨道耦合，当体系被调至电荷中性点时，该不对称性在决定量子自旋霍尔态所受自旋轨道相互作用方面可能占据主导地位。