Directly Measuring a Multiparticle Quantum Wave Function via Quantum Teleportation

TL;DR

This paper introduces a novel quantum teleportation-based method to directly measure multi-particle quantum wave functions, enabling efficient characterization of complex quantum states beyond traditional tomography.

Contribution

The authors present a new approach to measure multi-particle wave functions directly using quantum teleportation, demonstrated experimentally on photonic states, with exponential efficiency gains.

Findings

Successfully measured a multi-particle quantum wave function beyond single photons.

Implemented the method experimentally with photonic mixed states.

Achieved exponential reduction in measurement complexity compared to standard tomography.

Abstract

We propose a new method to directly measure a general multi-particle 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 wavefunction 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 multi-particle quantum state.