608 citations · 1.6k across the 14 of their papers we have counts for
14 papers
Co-tunneling spin blockade observed in a three-terminal triple quantum dot
A. Noiri, T. Takakura, T. Obata +4
We prepare a triple quantum dot with a separate contact lead to each dot to study Pauli spin blockade in the tunnel-coupled three dots in a row. We measure the tunneling current fl…
Robust micro-magnet design for fast electrical manipulations of single spins in quantum dots
Jun Yoneda, Tomohiro Otsuka, Tatsuki Takakura +9
Tailoring spin coupling to electric fields is central to spintronics and spin-based quantum information processing. We present an optimal micromagnet design that produces appropria…
Fast Electrical Control of Single Electron Spins in Quantum Dots with Vanishing Influence from Nuclear Spins
J. Yoneda, T. Otsuka, T. Nakajima +7
We demonstrate fast universal electrical spin manipulation with inhomogeneous magnetic fields. With fast Rabi frequency up to 127 MHz, we leave the conventional regime of strong nu…
Single to quadruple quantum dots with tunable tunnel couplings
Tatsuki Takakura, Akito Noiri, Toshiaki Obata +4
We prepare a gate-defined quadruple quantum dot to study the gate-tunability of single to quadruple quantum dots with finite inter-dot tunnel couplings. The measured charging energ…
Charge-noise-free Lateral Quantum Dot Devices with Undoped Si/SiGe Wafer
T. Obata, K. Takeda, J. Kamioka +6
We develop quantum dots in a single layered MOS structure using an undoped Si/SiGe wafer. By applying a positive bias on the surface gates, electrons are accumulated in the Si chan…
Characterization and Suppression of Low-frequency Noise in Si/SiGe Quantum Point Contacts and Quantum Dots
K. Takeda, T. Obata, Y. Fukuoka +5
We report on the effects of a global top gate on low-frequency noise in Schottky gate-defined quantum point contacts (QPCs) and quantum dots (QDs) in a modulation-doped Si/SiGe het…