Spin filtering through a single impurity in a GaAs/AlAs/GaAs resonant tunneling device

Abstract

The Zeeman splittings of a Si shallow donor in AlAs and of a two-dimensional electron gas ͑2DEG͒ in GaAs are evidenced by resonant tunneling spectroscopy in submicrometer GaAs/AlAs/GaAs junctions. In magnetic field, the donor acts as a spin-sensitive probe of the spin-polarized density of states in the emitter. In the current-voltage characteristic the two splittings are resolved, which allows us to estimate the Landé g factors for the impurity g I = + 1.96Ϯ 0.16 and for the 2DEG. Because of spin conservation in the tunneling between the 2DEG and the donor, the relative sign of the two g factors can be determined.

Probe and control of the reservoir density of states in single-electron devices

“…31 In contrast, Zeeman splitting of DOS peaks has been observed in tunneling through a Si shallow donor in a GaAs/AlAs/GaAs junction. 29 FIG. 4.…”

Spin-dependent tunneling rates for electrostatically defined GaAs quantum dots

“…In general the tunneling rates can be described with the local density of states in the lead ρ ↑/↓ and the tunneling probabilities through the barrier D ↑/↓ for spin-up/spin-down electrons [25]. The standard tunneling theory relates these parameters to the rates as ↑/↓ = (2π/ ) D ↑/↓ ρ ↑/↓ at the chemical potential μ ↑/↓ of the dot state [26].…”

Single-electron counting statistics with a finite frequency bandwidth

“…A large in-plane magnetic field (B = 8 T) is applied to induce significant Zeeman splitting. [26][27][28] The measurement was performed in a dilution refrigerator at 30 mK. The one-electron quantum dot has the addition energy of ³3 meV, orbital energy spacing of 1.2 meV, and the Zeeman energy splitting of 0.18 meV at 8 T. We focuse on the transport through the ground state (the spin-up Zeeman sublevel of the lowest orbital) in the following measurements.…”