Photon-Number-Dependent Hamiltonian Engineering for Cavities

TL;DR

This paper presents a method to engineer photon-number-dependent Hamiltonians in cavity resonators using ancilla qubits, enabling advanced quantum control and applications in quantum simulation and gate design.

Contribution

The authors develop an optimized scheme for creating arbitrary photon-number-dependent Hamiltonians via off-resonant driving of dispersively coupled ancilla qubits, reducing errors.

Findings

Successfully engineered photon-number-dependent Hamiltonians in cavities.

Demonstrated cancellation of cavity self-Kerr interactions.

Applicable to superconducting circuit systems with microwave cavities and transmon qubits.

Abstract

Cavity resonators are promising resources for quantum technology, while native nonlinear interactions for cavities are typically too weak to provide the level of quantum control required to deliver complex targeted operations. Here we investigate a scheme to engineer a target Hamiltonian for photonic cavities using ancilla qubits. By off-resonantly driving dispersively coupled ancilla qubits, we develop an optimized approach to engineering an arbitrary photon-number-dependent (PND) Hamiltonian for the cavities while minimizing the operation errors. The engineered Hamiltonian admits various applications including canceling unwanted cavity self-Kerr interactions, creating higher-order nonlinearities for quantum simulations, and designing quantum gates resilient to noise. Our scheme can be implemented with coupled microwave cavities and transmon qubits in superconducting circuit systems.