2023/05/20 by Ali Raza Mirza, Mirza, Ali Raza, Adam Zaman Chaudhry +1 · 1 citation
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Quantum and electron transport phenomena #Spectroscopy and Quantum Chemical Studies
paper · pdf · doi:10.48550/arxiv.2305.12278
openalex publication_date 2023/05/20 · openalex created_date 2023/05/24 · openalex updated_date 2026/07/28
We demonstrate how using two qubits can drastically improve the estimation of environment parameters as compared to using only a single qubit. The two qubits are coupled to a common harmonic oscillatorenvironment, and the properties of the environment are imprinted upon the dynamics of the two qubits. The reduced density matrix of only one of these qubits contains a decoherence factor as well as an additional factor taking into account the indirect interaction induced between the qubits due to the interaction with their common environment. This additional factor can drastically improve the estimation of the environment parameters, as quantified by the quantum Fisher information. In particular, we investigate the estimation of the cutoff frequency, the coupling strength, and the temperature using our two-qubit scheme as compared to simply using a single qubit. For super-Ohmic environments in particular, one can improve the precision of the estimates by orders of magnitude.