Directly Measuring a Multiparticle Quantum Wave Function via Quantum Teleportation
Ming-Cheng Chen, Yuan Li, Runze Liu, Dian Wu, Zu-En Su, Xi‐Lin Wang, Li Li, Nai-Le Liu, Chao‐Yang Lu, Jian-Wei Pan · Physical Review Letters · 2021
We propose a new method to directly measure a general multiparticle quantum wave function, a single matrix element in a multi-particle density matrix, by quantum teleportation. The density matrix element is embedded in a virtual logical qubit and is nondestructively teleported to a single physical qubit for readout. We experimentally implement this method to directly measure the wave function of a photonic mixed quantum state beyond a single photon using a single observable for the first time. Our method also provides an exponential advantage over the standard quantum state tomography in measurement complexity to fully characterize a sparse multiparticle quantum state.