Multispin Couplers for Quantum Information Processing

Quantum computing is a rapidly growing field, largely because its computation capabilities may surpass those of classical computing systems. Quantum computing holds great potential for solving complex problems that were once considered computationally infeasible. However, engineering qubit interactions—critical elements for constructing scalable quantum devices—has always been a challenging and limiting issue. Existing techniques mainly adopt perturbative methods that use several building blocks to construct the desired interaction. But these techniques possess limitations: they're not capable of directly engineering many-body interactions that involve multiple qubits simultaneously, they often result in undesirable interactions, and they lack scalability.

Technology Description

The technology, centered around superconducting Josephson-junction-based circuits, aims to develop physical multiqubit, or “many-qubit,” interactions in a nonperturbative manner. The system features a multispin coupler that includes numerous loops — each housing a pair of Josephson junctions — and multiple qubits that are each inductively linked with the multispin coupler. This technology is a significant advancement in the quantum computing landscape because it allows direct engineering of multiqubit interactions. The non-perturbative approach allows manipulating more universal classes of many-body interactions, which aren't possible with standard techniques. The Josephson junction-based circuits are an important component because of their superconductive properties, marking a significant threshold in the technological development of quantum computing systems.