Electron spin blockade and singlet-triplet transition in a silicon single electron transistor

Abstract

We investigate a silicon single-electron transistor (SET) in a metal-oxide-semiconductor (MOS) structure by applying a magnetic field perpendicular to the sample surface. The quantum dot is defined electrostatically in a point contact channel and by the potential barriers from negatively charged interface traps. The magnetic field dependence of the excitation spectrum is primarily driven by the Zeeman effect. In the two-electron singlet-triplet (ST) transition, electron-electron Coulomb interaction plays a significant role. The evolution of Coulomb blockade peaks with magnetic field B is also owing to the Zeeman splitting with no obvious orbital effect up to 9 T. The filling pattern shows an alternate spin-up-spin-down sequence. The amplitude spectroscopy allows for the observation of the spin blockade effect, where the two-electron system forms a singlet state at low fields, and the spin polarized injection from the lead reduces the tunneling conductance by a factor of 8. At a higher magnetic field, due to the ST transition, the spin blockade effect is lifted and the conductance is fully recovered.

8 pages, 5 figures, submitted to Physical Review B

References in corpus (7)

• Driven coherent oscillations of a single electron spin in a quantum dot
• Transport spectroscopy of a single dopant in a gated silicon nanowire
• Controllable valley splitting in silicon quantum devices
• Valley Polarization in Si(100) at Zero Magnetic Field
• Pauli-Spin-Blockade Transport through a Silicon Double Quantum Dot
• Single-electron quantum dot in Si/SiGe with integrated charge-sensing
• Coulomb blockade in a Si channel gated by an Al single-electron transistor

Cited by in corpus (8)

• Hubbard model description of silicon spin qubits: charge stability diagram and tunnel coupling in Si double quantum dots
• Spin filling of valley-orbit states in a silicon quantum dot
• Double quantum dot with tunable coupling in an enhancement-mode silicon metal-oxide semiconductor device with lateral geometry
• Electrostatically defined Quantum Dots in a Si/SiGe Heterostructure
• Singlet-triplet relaxation in SiGe/Si/SiGe double quantum dots
• Detection of a single-charge defect in a metal-oxide-semiconductor structure using vertically coupled Al and Si single-electron transistors
• Determining the Location and Cause of Unintentional Quantum Dots in a Nanowire
• Effect of device design on charge offset drift in Si/SiO${}_2$ single electron devices