Probing hole spin transport of disorder quantum dots via Pauli spin-blockade in standard silicon transistors.

Single hole transport and spin detection is achievable in standard p-type silicon transistors owing to the strong orbital quantization of disorder based quantum dots. Through the use of the well acting as a pseudo-gate, we discover the formation of a double-quantum dot system exhibiting Pauli spin-blockade and investigate the magnetic field dependence of the leakage current. This enables attributes that are key to hole spin state control to be determined, where we calculate a tunnel couplingtcof 57µeV and a short spin-orbit lengthlSOof 250 nm. The demonstrated strong spin-orbit interaction at the interface when using disorder based quantum dots supports electric-field mediated control. These results provide further motivation that a readily scalable platform such as industry standard silicon technology can be used to investigate interactions which are useful for quantum information processing.

Manipulation of random telegraph signals in a silicon nanowire transistor with a triple gate.

Manipulation of carrier densities at the single electron level is inevitable in modern silicon based transistors to ensure reliable circuit operation with sufficiently low threshold-voltage variations. However, previous methods required statistical analysis to identify devices which exhibit random telegraph signals (RTSs), caused by trapping and de-trapping of a single electron. Here, we show that we can deliberately introduce an RTS in a silicon nanowire transistor, with its probability distribution perfectly controlled by a triple gate. A quantum dot (QD) was electrically defined in a silicon nanowire transistor with a triple gate, and an RTS was observed when two barrier gates were negatively biased to form potential barriers, while the entire nanowire channel was weakly inverted by the top gate. We could successfully derive the energy levels in the QD from the quantum mechanical probability distributions and the average lifetimes of RTSs. This study reveals that we can manipulate individual electrons electrically, even at room temperature, and paves the way to use a charged state for quantum technologies in the future.

Silicon slot fin waveguide on bonded double-SOI for a low-power accumulation modulator fabricated by an anisotropic wet etching technique.

We propose a new low VπL, fully-crystalline, accumulation modulator design based on a thin horizontal gate oxide slot fin waveguide, on bonded double Silicon-on-Insulator (SOI). A combination of anisotropic wet etching and the mirrored crystal alignment of the top and bottom SOI layers allows us for the first time to selectively pattern the bottom layer from above. Simulations presented herein show a VπL = 0.17Vcm. Fin-waveguides and passive Mach-Zehnder Interferometer (MZI) devices with fin-waveguide phase shifters have been fabricated, with the fin-waveguides having a transmission loss of 5.8dB/mm and a 13.5nm thick internal gate oxide slot.