Resonant frequency control of electron spin in SiMOS quantum dot using magnetic field generated by external current

Electron spin qubits employing Si quantum dots are considered promising candidates for realizing large-scale quantum computers, as they can leverage established LSI integration technologies [1]. Electron spin states can be controlled by applying microwave pulses at a resonant frequency corresponding to the energy difference between the spin-up and spin-down states [2]. To selectively address and control an arbitrary qubit among many, it is necessary to tune each qubit's resonant frequency to a distinct value. In this work, we propose a method to shift the resonant frequency of electron spins by generating a localized magnetic field around the qubit through passing a current near a quantum dot. This approach allows for dynamic control of the resonant frequency by adjusting the current, thus enabling highly flexible selection and manipulation of spin qubits. We fabricated a silicon MOS quantum dot device integrated with a microstrip line to demonstrate the feasibility of controlling the electron spin resonance frequency via external electric current. This technique can be combined with other qubit selection methods [3], making it a versatile tool with broad applications in the development of large-scale quantum computing.

[1] M. Veldhorst et al., Nat. Nanotechnol. 9, 981 (2014).

[2] J. J. Pla et al., Nature 496, 334 (2013).

[3] K. Takeda et al., Sci. Adv. 2, e1600694 (2016).