Radio-Frequency Capacitive Gate-Based Sensing

Imtiaz Ahmed (1) , James A. Haigh (2) , Simon Schaal (3) , Sylvain Barraud (4) , Yi Zhu (5) , Chang-Min Lee (5) , Mario Amado (5) , Jason W. A. Robinson (5) , Alessandro Rossi (1) , John J. L. Morton (3, 6) , M Fernando Gonzalez-Zalba (2)

1 Cavendish Laboratory
2 Hitachi Cambridge Laboratory [University of Cambridge]
3 London Centre for Nanotechnology
4 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
5 DMSM - Department of Materials Science and Metallurgy [Cambridge University]
6 UCL - University College of London [London]

Developing fast, accurate, and scalable techniques for quantum-state readout is an active area in semiconductor-based quantum computing. Here, we present results on dispersive sensing of silicon corner state quantum dots coupled to lumped-element electrical resonators via the gate. The gate capacitance of the quantum device is placed in parallel with a superconducting spiral inductor resulting in resonators with loaded $Q$ factors in the 400-800 range. We utilize resonators operating at 330 and 616 MHz, and achieve charge sensitivities of 7.7 and 1.3 $\mu$e $\sqrt Hz$, respectively. We perform a parametric study of the resonator to reveal its optimal operation points and perform a circuit analysis to determine the best resonator design. The results place gate-based sensing on a par with the best reported radio-frequency single-electron transistor sensitivities while providing a fast and compact method for quantum-state readout.

Domaines: Sciences de l'ingénieur [physics]

Imtiaz Ahmed, James A. Haigh, Simon Schaal, Sylvain Barraud, Yi Zhu, et al.. Radio-Frequency Capacitive Gate-Based Sensing. Physical Review Applied, 2018, 10, pp.0104018. ⟨10.1103/PhysRevApplied.10.014018⟩. ⟨cea-02184686⟩