Asymmetric blockade and multi-qubit gates via dipole-dipole interactions

TL;DR

This paper introduces a method for multi-qubit gates using asymmetric Rydberg blockade, enabling efficient quantum state preparation and simplifying quantum algorithms with high fidelity.

Contribution

It generalizes two-qubit Rydberg blockade gates to multi-qubit gates with asymmetric interactions using microwave dressing, improving scalability and efficiency.

Findings

A 25-atom GHZ state can be generated with only three gates.

The proposed gates achieve an error rate of 7.8%.

Asymmetric blockade simplifies multi-qubit quantum operations.

Abstract

Due to their strong and tunable interactions, Rydberg atoms can be used to realize fast two-qubit entangling gates. We propose a generalization of a generic two-qubit Rydberg-blockade gate to multi-qubit Rydberg-blockade gates which involve both many control qubits and many target qubits simultaneously. This is achieved by using strong microwave fields to dress nearby Rydberg states, leading to asymmetric blockade in which control-target interactions are much stronger than control-control and target-target interactions. The implementation of these multi-qubit gates can drastically simplify both quantum algorithms and state preparation. To illustrate this, we show that a 25-atom GHZ state can be created using only three gates with an error of 7.8%.