Control protocols for scalable photon-mediated operations in quantum information processing

Efficient light-matter interfaces between qubits with initially different spectral signatures represent a key challenge for the construction of scalable quantum platforms. This is particularly important for promising hybrid architectures where different qubit modalities are to be used for their most advantageous properties. The problem also arises in nominally identical qubits that are nevertheless different in their operating frequencies due to variations in the fabrication process or in the solid state environment. Here, we examine two-qubit operations between spectrally different systems and demonstrate optimization with post-fabrication procedures in the form of externally applied control fields [1,2]. To this end, we use a combination of analytical and computational methods to characterize the efficiency of our proposed control protocols on entanglement generation and two-qubit gates between disparate qubits. We supplement our analytical and numerical solutions with quantum algorithms compatible with existing NISQ (noisy intermediate state quantum) systems, to solve fundamental quantum optics models describing photon-mediated operations in quantum information processing [3,4]. Altogether, we are able to identify enhancements achieved in properties of single qubits, two-qubit systems and ensembles of qubits for qubit modalities that are susceptible to broad spectral variability.

[1] H. F. Fotso et al., Phys. Rev. Lett. 116, 033603 (2016). https://doi.org/10.1103/PhysRevLett.116.033603

[2] H. F. Fotso, Phys. Rev. B 100, 094309 (2019). https://doi.org/10.1103/PhysRevB.100.094309

[3] H. F. Fotso et al., Optics and Photonics for Information Processing XIX 13604, 125-132 (2025). https://doi.org/10.1117/12.3065016

[4] S. S. Yuvarajan et al., ArXiv:2512.12030 (2025). https://doi.org/10.48550/arXiv.2512.12030