Experimental demonstration of optimal measurement for unambiguously discriminating asymmetric qudit states

Abstract

Identification of nonorthogonal quantum states without error is crucial for various applications in quantum information technology, as well as the foundations of quantum physics. Theoretical studies have proposed measurements that maximize the success probability of unambiguously discriminating quantum states. However, these methods are not always experimentally feasible, which has led most demonstrations to focus on equiprobable symmetric states. Here, we establish a projective measurement scheme that optimally discriminates multiple asymmetric qudit states. We experimentally demonstrate this optimal projective measurement using a photonic orbital angular momentum state, where asymmetric qudit states are encoded in the Laguerre-Gaussian modes of a heralded single-photon state. Our results have broad applications in high-dimensional quantum state-based quantum information processing, including quantum key distribution and quantum sensing.

13 pages, 9 figures

References in corpus (6)

• A randomized quantum algorithm for statistical phase estimation
• Quantum algorithm for ground state energy estimation using circuit depth with exponentially improved dependence on precision
• Measuring the Loschmidt amplitude for finite-energy properties of the Fermi-Hubbard model on an ion-trap quantum computer
• Probing finite-temperature observables in quantum simulators of spin systems with short-time dynamics
• Statistical phase estimation and error mitigation on a superconducting quantum processor
• Phase-Sensitive Quantum Measurement without Controlled Operations