2016/04/30 by Ryo Mizuta, R. Mizuta, R. M. Otxoa +3
Computer Science · Engineering · Physics and Astronomy · #Capacitance #Charge (physics) #Condensed matter physics #Electrode #Molecular Junctions and Nanostructures #Physics #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum mechanics #Quantum tunnelling #Qubit #Spin (aerodynamics) #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.95.045414
published as Phys. Rev. B 95, 045414 (2017) · 9 pages, 6 figures
openalex created_date 2016/06/24 · arxiv created 2016/08/16 · openalex publication_date 2017/01/18 · arxiv updated 2017/01/25 · openalex updated_date 2026/08/05
We present a theoretical analysis of the capacitance of a double quantum dot in the charge and spin qubit configurations probed at high frequencies. We find that, in general, the total capacitance of the system consists of two state-dependent terms: the quantum capacitance arising from adiabatic charge motion and the tunneling capacitance that appears when repopulation occurs at a rate comparable or faster than the probing frequency. The analysis of the capacitance lineshape as a function of externally controllable variables offers a way to characterize the qubits' charge and spin state as well as relevant system parameters such as charge and spin relaxation rates, tunnel coupling, electron temperature, and electron g factor. Overall, our analysis provides a formalism to understand dispersive qubit-resonator interactions which can be applied to high-sensitivity and noninvasive quantum-state readout.