Electrical Control of g-Factor in a Few-Hole Silicon Nanowire MOSFET

Abstract

Hole spins in silicon represent a promising yet barely explored direction for solid-state quantum computation, possibly combining long spin coherence, resulting from a reduced hyperfine interaction, and fast electrically driven qubit manipulation. Here we show that a silicon-nanowire field-effect transistor based on state-of-the-art silicon-on-insulator technology can be operated as a few-hole quantum dot. A detailed magnetotransport study of the first accessible hole reveals a g-factor with unexpectedly strong anisotropy and gate dependence. We infer that these two characteristics could enable an electrically driven g-tensor-modulation spin resonance with Rabi frequencies exceeding several hundred mega-Hertz.

Pauli blockade in a few-hole PMOS double quantum dot limited by spin-orbit interaction

“…smaller than the current dip width of 10-20 mT [14,28]. Γ SO is larger than in previous reports [13,19] while the critical field B C is comparable to that of refs.…”

Consequences of Spin-Orbit Coupling at the Single Hole Level: Spin-Flip Tunneling and the Anisotropic g Factor

“…In Fig. 3(c) we set the dramatic anisotropy demonstrated in our experiment against the measurements in SADs [20] and silicon nanowire hole QDs [21], where the LH subband is confined, and in consequence the hole g-factor does not reach zero for in-plane magnetic field.…”

“…In this regime the strong anisotropy of the hole g-factor is expected [12]. To date, however, only partial anisotropy was demonstrated, e.g., in InAs SADs [20] and silicon nanowires [21]. Holes in GaAs are also subject to strong Dreselhaus and Rashba spin-orbit interactions, which introduce the coherent spin-flip tunneling [12,13].…”

“…Holes in GaAs are also subject to strong Dreselhaus and Rashba spin-orbit interactions, which introduce the coherent spin-flip tunneling [12,13]. In silicon DQDs these interactions are absent, leading to Pauli spin blockade [21][22][23]. On the other hand, early experiments on GaAs DQDs in many-hole regime show the spin-orbit-induced spin-flip transport [25].…”

Spin blockade in hole quantum dots: Tuning exchange electrically and probing Zeeman interactions

“…The period of the anisotropic leakage is critically dependent on the relative magnitude of Zeeman interaction terms linear and cubic in the magnetic field. The current and singlet-triplet exchange splitting can be effectively adjusted by an appropriate choice of field direction, providing a simple control variable for quantum information processing and a way of tailoring magnetic interactions in hole spin qubits.Spin-based quantum information processing platforms relying on hole quantum dots (QDs) have recently attracted considerable attention [1][2][3][4][5][6][7][8][9][10][11], since they permit long spin coherence and electrically driven spin resonance thanks to the strong hole spinorbit (SO) interaction [12][13][14][15][16][17][18][19][20]. Owing to their effective spin J = 3 2 , spin dynamics in hole systems often exhibits physics not found in electron systems [21][22][23][24][25][26].…”