Harnessing Non-Hermitian Hamiltonians: Advancements in NISQ-era Superconducting Qubit Technologies

In our study, we evolve IBM's NISQ superconducting qubits under a non-Hermitian Hamiltonian using a variational quantum circuit. The parameters of this circuit are optimized through a machine learning approach specifically tailored for non-unitary operations, allowing us to observe non-Hermitian phenomena with various observables, including probability and magnetization. We further explore the outcomes of tomography experiments on a non-Hermitian qubit over time. Utilizing an entangled qubit pair, we demonstrate the ability to modify concurrence through local operations, leading to violations of entanglement monotones. Our findings highlight the considerable challenges in quantum computing, notably the intricacies of implementing non-Hermitian behavior.