Victor D. A. Avella (Universidad de Antofagasta, Chile): Quantum State Tomography Beyond Ten Qubits

Víctor Daniel González Avella (Universidad de Antofagasta, Antofagasta, Chile).
Quantum State Tomography Beyond Ten Qubits.
Resources required to reconstruct the global state of a quantum computer typically scale exponentially with the number of involved qubits, namely number of quantum circuits, number non-local gates and postprocessing time. Despite many quantum state tomography protocols are known, see e.g., [1-5], none of them optimize all the above mentioned aspects, as far as we know. In this work, we provide a tomographic method that considers 2n + 1 quantum circuits for n-qubit systems, each of them composed by a single Pauli gate in each qubit, in the measurement stage. As further advantages, we provide an explicit reconstruction formula, whereas postprocessing is not required to estimate a valid quantum state. This protocol has been tested on IBM quantum computers obtaining high fidelities for genuinely entangled states up to 10 qubits. These results push forward the boundaries of state tomography in quantum computers beyond 10 qubits in the NISQ era [6].
[1] Phys. Rev. Lett. 105, 150401 (2010)
[2] Nature Comm. 1, 149 (2010)
[3] Phys. Rev. Lett. 115, 090401 (2015)
[4] Npj Quant.Inf. 8, 57 (2022)
[5] Phys. Rev. A 107, 012408 (2023)
[6] Quantum 2, 79 (2018)
Quantum Information and Quantum Computing Seminars CTP PAS
2024-11-06