g-tensor resonance in double quantum dots with site-dependent g-tensors

Abstract

Pauli spin blockade (PSB) has long been an important tool for spin read-out in double quantum dot (DQD) systems with interdot tunneling t. In this paper we show that the blockade is lifted if the two dots experience distinct effective magnetic fields caused by site-dependent g-tensors g L and g R for the left and right dot, and that this effect can be more pronounced than the leakage current due to the spin–orbit interaction (SOI) via spin-flip tunneling and the hyperfine interaction (HFI) of the electron spin with the host nuclear spins. Using analytical results obtained in special parameter regimes, we show that information about both the out-of-plane and in-plane g-factors of the dots can be inferred from characteristic features of the magneto-transport curve. For a symmetric DQD, we predict a pronounced maximum in the leakage current at the characteristic out-of-plane magnetic field B * = t / μ B g z L g z R which we term the g-tensor resonance of the system. Moreover, we extend the results to contain the effects of strong SOI and argue that in this more general case the leakage current carries information about the g-tensor components and SOI of the system.

Phonon-assisted relaxation between triplet and singlet states in a self-assembled double quantum dot

“…While such a Hamiltonian conserves the projection of the total angular momentum , it does not commute with the operator, hence mixes the states belonging to different representations of the rotation group. This mixing effect was shown to be an important factor determining transport properties of a gate-defined double quantum dot 29 . Such an effect takes place only for many-body configurations.…”

“…In the first case, the spin relaxation times on the order of hundreds of micro-seconds were predicted for relatively low barriers and large dots, growing by orders of magnitude when the barrier height increases or the QD size decreases 23 . It has been shown 29 , that a difference between the site-dependent g-tensors in a QDM couples singlet to triplet states changing the leakage current.…”

All-electrical control of hole singlet-triplet spin qubits at low leakage points

“…[37] to unburden the notation and lighten the expressions later on. Information about the spin-orbit vector may be obtained, e.g., via magneto-transport measurements [38,39]. Higher order contributions due to the SOI are possible but suppressed when the orbital spacing induced by the confine- ment potentials is the largest energy scale in the system [40].…”

Line Shapes of Electric Dipole Spin Resonance in Pauli Spin Blockade

“…Previous similar theoretical studies of EDSR in the spin-blockade regime focused on mechanism (i ) in the strong-driving limit [44,45,47] or on mechanism (ii ) in the absence of both SOI and coherent interdot coupling [48][49][50][51]. Other related studies focus on a lifting of the Pauli spin blockade in the presence of SOI and hyperfine coupling but without an external driving of the system [52,53]. Here, we want to focus on the weak-driving limit, where the amplitude of the drivinginduced effective oscillating magnetic field in the (1,1) subspace is always smaller than the level splittings we want to probe.…”