Localized electron spins in semiconductors are one of the prominent candidates for developing quantum computing devices. Recent progress has demonstrated high fidelities of single-qubit and two-qubit gate operations as well as qubit state measurements. But the number of qubits in the state-of-the-art experiments is still relatively low compared with other qubit device platforms, and the use of micromagnets to implement single spin rotations via electric dipole spin resonance (EDSR) may be a restriction in scaling up the devices. An alternative approach is to encode qubits in multi-spin systems which enable all electrical control of the qubit gate operations. This exchange-coupling-based approach can be a viable route for scalable quantum computing devices in semiconductor systems.<br/>We present some strategies to mitigate the effects of the charge noise which is the dominant source of decoherence for these devices. Controlling the exchange interaction between individual spins while maintaining the system to be insensitive to the charge noise can increase the coherence significantly. Both electron and hole spin qubits are considered for effective encoding of qubits and gate operations, and some novel Pauli spin blockade effects in resonant triple quantum dot molecules, which can be used for encoded qubits in such systems, are presented.

Semiconductor quantum dot spin qubits and encoded qubits

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.