Coherence Time of a Semiconductor Hybrid Qubit in Presence of Environmental Noises

The effects of magnetic and charge noises on the dynamics of the hybrid qubit [1] (HQ) is theoretically investigated. The HQ consisting of three electrons arranged in a double quantum dot deserves special interest in quantum computation applications due to its advantages in terms of fabrication, control and manipulation in view of implementation of fast operations through only electrical tuning. The presence of the environmental noise due to nuclear spins and charge traps, in addition to fluctuations in the applied magnetic field and charge fluctuations on the electrostatic gates, is taken into account including random magnetic field and random coupling terms in the Hamiltonian [2]. The dymanics of the return probability for two initial conditions of interest is presented when HQs are hosted in ²⁸Si, natural Si and GaAs [3]. Coherence time of HQs is extracted when model parameters take values achievable experimentally, providing interesting predictions on its maximization. [1] Z. Shi et al., Phys. Rev. Lett. 108, 140503 (2012). [2] R.E. Throckmorton et al.,, Phys. Rev. B 95, 085405 (2017). [3] E. Ferraro et al., arXiv:1710.10032