2020/08/11 by Julia Cen, Avadh Saxena, Cen, Julia +1 · 3 citations
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Mechanics and Non-Hermitian Physics #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2008.04514
openalex publication_date 2020/08/11 · openalex created_date 2020/08/18 · openalex updated_date 2026/07/28
We investigate a two-level spin system based anti-parity-time (anti-PT)-symmetric qubit and study its decoherence as well as entanglement entropy properties. We compare our findings with that of the corresponding PT-symmetric and Hermitian qubits. First we consider the time-dependent Dyson map to find the exact analytical dynamics for a general non-Hermitian qubit system coupled with a bath, then we specialize it to the case of the anti-PT-symmetric qubit. We find that the decoherence function for the anti-PT-symmetric qubit decays slower than the PT-symmetric and Hermitian qubits. For the entanglement entropy we find that for the anti-PT-symmetric qubit it grows more slowly compared to the PT-symmetric and Hermitian qubits. Similarly, we find that the corresponding variance and area of Fisher information is much higher compared to the PT-symmetric and Hermitian qubits. These results demonstrate that anti-PT-symmetric qubits may be better suited for quantum computing and quantum information processing applications than conventional Hermitian or even PT-symmetric qubits.