Enabling Modularity for Spin Qubits via Driven Quantum Dot-Mediated Entanglement

TL;DR

This paper introduces a driven quantum dot-mediated entanglement method for spin qubits, enabling rapid, single-pulse universal gates without complex pulse sequences, and discusses its integration with cavity-mediated entangling approaches.

Contribution

The authors propose a novel driven quantum dot approach for capacitive entanglement of spin qubits, enhancing modularity and simplifying gate implementation.

Findings

Enables rapid, single-pulse entangling gates for resonant exchange qubits.

Does not require extensive pulse sequences to mitigate leakage.

Can be integrated with cavity-mediated entangling methods for modular quantum computing.

Abstract

We present an approach for entangling spin qubits via capacitive coupling mediated by an ac electric field-driven multielectron mediator quantum dot. To illustrate this method, we consider the case of a driven two-electron dot that mediates entanglement between resonant exchange qubits defined in three-electron triple quantum dots, which enable direct capacitive coupling and interaction with microwave fields via intrinsic spin-charge mixing. The method can also be applied to other types of spin qubits that can be coupled capacitively. We show that this approach leads to rapid, single-pulse universal entangling gates for resonant exchange qubits that are activated via the drive on the mediator dot. Unlike conventional tunneling-based two-qubit gates between exchange-only qubits, the capacitive interaction-based gates we describe do not require an extensive sequence of pulses to mitigate leakage. We describe how this drive-activated local entangling approach can be integrated with the driven sideband-based long-range approach for cavity-mediated entangling gates developed in our previous work in order to enable modularity for spin-based quantum information processing.