Bandwidth-Limited and Noisy Pulse Sequences for Single Qubit Operations in Semiconductor Spin Qubits

Elena Ferraro,Marco De Michielis

doi:10.3390/e21111042

Abstract

Spin qubits are very valuable and scalable candidates in the area of quantum computation and simulation applications. In the last decades, they have been deeply investigated from a theoretical point of view and realized on the scale of few devices in the laboratories. In semiconductors, spin qubits can be built confining the spin of electrons in electrostatically defined quantum dots. Through this approach, it is possible to create different implementations: single electron spin qubit, singlet–triplet spin qubit, or a three-electron architecture, e.g., the hybrid qubit. For each qubit type, we study the single qubit rotations along the principal axis of Bloch sphere including the mandatory non-idealities of the control signals that realize the gate operations. The realistic transient of the control signal pulses are obtained by adopting an appropriate low-pass filter function. In addition. the effect of disturbances on the input signals is taken into account by using a Gaussian noise model.

Highlights

The confinement of electron spins in host semiconductors is intensely studied in view of powerful applications in quantum computation and simulation [1,2,3,4]
Starting from analytical expressions for the realization of logical gates, which are rotations along the main axis on the Bloch sphere, we study how such operations are affected when non-idealities are included in the control pulses
We focus our study on three QD spin qubits: the single spin qubit [13], the singlet-triplet qubit [14]

Summary

Introduction

The confinement of electron spins in host semiconductors is intensely studied in view of powerful applications in quantum computation and simulation [1,2,3,4]. Studied are qubit defined in electrostatically or self-assembled QDs [5,6,7], donor spins in solid matrices [8,9,10] or a combination of them [11,12]. Semiconductor-based qubits assure long electron spin coherence times, easy manipulation, fast gate operations, and potential for scaling, in addition to the compatibility with the existing CMOS process. Starting from analytical expressions for the realization of logical gates, which are rotations along the main axis on the Bloch sphere, we study how such operations are affected when non-idealities are included in the control pulses. We focus our study on three QD spin qubits: the single spin qubit [13], the singlet-triplet qubit [14]

Methods

Results

Conclusion