Abstract
The exponential growth in Hilbert space with increasing size of a quantum system means that accurately characterizing the system becomes significantly harder with system dimension . We show that self-guided tomography is a practical, efficient, and robust technique of measuring higher-dimensional quantum states. The achieved fidelities are over 99.9% for qutrits () and ququints (), and 99.1% for quvigints ()—the highest values ever realized for qudit pure states. We also show excellent performance for mixed states, achieving average fidelities of 96.5% for qutrits. We demonstrate robustness against experimental sources of noise, both statistical and environmental. The technique is applicable to any higher-dimensional system, from a collection of qubits through to individual qudits, and any physical realization, be it photonic, superconducting, ionic, or spin.
- Received 1 October 2020
- Revised 12 January 2021
- Accepted 5 February 2021
DOI:https://doi.org/10.1103/PhysRevLett.126.100402
© 2021 American Physical Society
Physics Subject Headings (PhySH)
synopsis
Measuring Higher Dimensional “Qudits” for Computation
Published 10 March 2021
With a technique called self-guided tomography, researchers accurately measure the states of qudits—quantum systems like qubits but with more than two dimensions.
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