Single-operation Rydberg Phase Gates Via Dynamic Suppression Enables High-Fidelity Computation

Neutral atoms represent a promising platform for quantum computing, but achieving both speed and accuracy in manipulating these systems remains a significant challenge. Sebastian C. Carrasco, Jabir Chathanathil, and Svetlana A. Malinovskaya, working with colleagues at the DEVCOM Army Research Laboratory and Stevens Institute of Technology, alongside Ignacio Sola from Universidad Complutense and Vladimir S. Malinovsky, now demonstrate a new method for creating highly accurate quantum operations. The team achieves this by precisely controlling the excitation of atoms to a special, highly interactive state known as a Rydberg state, dynamically suppressing unwanted behaviour while retaining the crucial interactions needed to link quantum bits. This innovative approach defines a new operational regime, simultaneously boosting speed, fidelity, and robustness, and offers a compelling pathway towards building scalable and reliable quantum computers based on neutral atom technology.

Dynamic Suppression for High Fidelity Rydberg Gates

Scientists propose a versatile control protocol using modulated fields to implement high-fidelity single-qubit and two-qubit Rydberg phase gates. This method leverages dynamic population suppression to minimize detrimental effects of spontaneous emission and unwanted excitation during gate operation, enabling precise control over qubit interactions. By optimizing pulse parameters, the team demonstrates the potential to achieve gate fidelities exceeding 99. 9% for both single- and two-qubit operations, significantly improving the performance of quantum circuits. This technique offers a robust and efficient pathway towards scalable quantum computation, reducing the need for complex error correction schemes and enhancing the overall coherence of quantum systems. Areas of investigation include creating and controlling atom arrays, understanding their interactions, scaling up array size, and applying them to quantum simulation, computation, and information processing. Researchers are also exploring the use of Rydberg atoms for precise measurements and sensing applications, alongside developing advanced control techniques for manipulating atomic states. Key techniques include optical tweezers for trapping atoms, laser cooling and trapping, microwave control of atomic states, and pulse shaping to precisely control atomic interactions. By employing modulated excitation pulses, scientists dynamically suppress unwanted Rydberg state population while preserving the crucial Rydberg-Rydberg interactions needed for entanglement. This approach achieves nearly ideal controlled-Z gates across a broad range of interaction strengths, offering ultrafast operation times that scale inversely with the blockade energy. The team’s method minimizes errors stemming from Rydberg state decay during gate execution and exhibits robust performance even with realistic experimental imperfections. A key advantage of this technique is the existence of numerous optimal parameter settings, providing experimentalists with considerable flexibility to adapt the protocol to different atom-trap configurations and laser systems. This dynamic suppression approach unifies the benefits of previously developed schemes, achieving high-fidelity, single-operation phase gates with scalable potential, paving the way for next-generation neutral-atom quantum processors.