Universal non-adiabatic geometric manipulation of pseudo-spin charge qubits

TL;DR

This paper proposes a feasible scheme for high-speed, robust quantum gates in nano-engineered charge qubits using non-adiabatic holonomic control, enabling universal quantum computation within short coherence times.

Contribution

It introduces a novel method for implementing high-fidelity geometric quantum gates in charge qubits via non-adiabatic holonomic techniques, including two-qubit entangling gates.

Findings

Demonstrates robust single-qubit rotations through controlled inter-dot tunneling.

Shows capacitive coupling enables non-adiabatic holonomic two-qubit gates.

Analyzes gate fidelities indicating feasibility of the proposed scheme.

Abstract

Reliable quantum information processing requires high-fidelity universal manipulation of quantum systems within the characteristic coherence times. Non-adiabatic holonomic quantum computation offers a promising approach to implement fast, universal, and robust quantum logic gates particularly useful in nano-fabricated solid-state architectures, which typically have short coherence times. Here, we propose an experimentally feasible scheme to realize high-speed universal geometric quantum gates in nano-engineered pseudo-spin charge qubits. We use a system of three coupled quantum dots containing a single electron, where two computational states of a double quantum dot charge qubit interact through an intermediate quantum dot. The additional degree of freedom introduced into the qubit makes it possible to create a geometric model system, which allows robust and efficient single-qubit rotations through careful control of the inter-dot tunneling parameters. We demonstrate that a capacitive coupling between two charge qubits permits a family of non-adiabatic holonomic controlled two-qubit entangling gates, and thus provides a promising procedure to maintain entanglement in charge qubits and a pathway toward fault-tolerant universal quantum computation. We estimate the feasibility of the proposed structure by analyzing the gate fidelities to some extent.