2024/08/23 by Abhishek Shukla, Boo Carmans, Shukla, Abhishek +6
Biochemistry, Genetics and Molecular Biology · Materials Science · Physics and Astronomy · #Advanced Electron Microscopy Techniques and Applications #Diamond and Carbon-based Materials Research #FOS: Physical sciences #Force Microscopy Techniques and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2408.13349
openalex publication_date 2024/08/23 · openalex created_date 2024/09/21 · openalex updated_date 2026/07/28
We report on a new quantum state characterisation method, which we call Rabi-based Quantum State Tomography (RQST), that we have validated on single-qubit quantum states, in particular on the electron and nuclear spins of a single nitrogen-vacancy (NV) centre in diamond, demonstrating high fidelities. The difference of RQST with conventional tomography methods is in the implementation of rotation operators and construction of density matrix from the measured data sets. We demonstrate efficient quantum state control of the electron spin at room temperature with an average fidelity of 0.995 over more than 40 measurements on different states on the Bloch sphere with a maximum fidelity of 0.99992. Also, we apply the methodology to the dark NV nuclear spin state. The state is read via the electron spin using the C-NOT two-qubit entanglement gate and demonstrate fidelities of the same order.