Performance engineering of semiconductor spin qubit systems

TL;DR

This paper investigates the performance of semiconductor spin qubit systems, focusing on how system parameters influence noise and gate operation times, with implications for optimizing quantum computation efficiency.

Contribution

It introduces a detailed analysis of noise sources and gate operation times in magnetic impurity spin qubits, highlighting how controllable parameters affect system performance.

Findings

Maximum quantum operations per coherence time increase as electron spin singlet-triplet gap decreases.

Magnetic impurities outperform electrons in weak coupling and large magnetic fields.

System size, geometry, and external fields significantly influence noise and gate times.

Abstract

The performance of a quantum computation system is investigated, with qubits represented by magnetic impurities in coupled quantum dots filled with two electrons. Magnetic impurities are electrically manipulated by electrons. The dominant noise source is the electron mediated indirect coupling between magnetic impurities and host spin bath. As a result of the electron mediated coupling, both noise properties and the time needed for elementary gate operations, depend on controllable system parameters, such as size and geometry of the quantum dot, and external electric and magnetic fields. We find that the maximum number of quantum operations per coherence time for magnetic impurities increases as electron spin singlet triplet energy gap decreases. The advantage of magnetic impurities over electrons for weak coupling and large magnetic fields will be illustrated.