Transport spectroscopy of a spin-orbit-coupled spin to a quantum dot

Abstract

Electron spins in quantum dots can interact with impurity spins located in an adjacent region. This interaction may be controllable using external electric fields and it can involve an appreciable spin-orbit interaction (SOI) part affecting the expected operation of the dot spins. In this work we propose a method to quantify the interaction between a dot spin and a nearby spin by calculating the electrical current through the dot. We demonstrate some interesting regimes where the SOI can be detected, and find regimes of negative differential conductance which are sensitive to the strength of the SOI. The present study could be useful for spin-orbit qubits formed in quantum dot devices.

Anisotropic g-Factor and Spin–Orbit Field in a Germanium Hut Wire Double Quantum Dot

“…The spin–orbit interaction (SOI) can be considered as a coupling between the momentum of a carrier and its spin. When an electron or hole moves in an electric field, it experiences an effective magnetic field that couples to its spin degree of freedom, even in the absence of an external magnetic field. − Recently, studies on the SOI have received widespread attention because of its fundamental role in both classical spintronics and the quantum coherent manipulation of a spin qubit, − and more recently in the search for Majorana fermions. − The SOI can be exploited for all-electrical manipulation of a spin–orbit qubit using electric dipole spin resonance (EDSR) techniques. − ,− Without generating a local ac magnetic field or making use of an external source of spin-electric coupling (such as micromagnets), the device design is simplified by using a local ac electric field. In addition, as proposed by theory and confirmed by recent experiments, a strong SOI is required to create Majorana fermions in semiconductor–superconductor heterostructures. − ,, Thus, the potential applications of the SOI for quantum information processing will be particularly relevant in the future, especially with respect to fast operation speed, scalability, and topological quantum computation …”