Experimental joint quantum measurements with minimum uncertainty.
Quantum physics constrains the accuracy of joint measurements of incompatible observables. Here we test tight measurement-uncertainty relations using single photons. We implement two independent, idealized uncertainty-estimation methods, the three-state method and the weak-measurement method, and adapt them to realistic experimental conditions. Exceptional quantum state fidelities of up to 0.999 98(6) allow us to verge upon the fundamental limits of measurement uncertainty.
Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia and Centre for Quantum Computer and Communication Technology, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia.
Martin
M
Ringbauer
Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia and Centre for Quantum Computer and Communication Technology, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia.
Devon N
DN
Biggerstaff
Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia and Centre for Quantum Computer and Communication Technology, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia.
Matthew A
MA
Broome
Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia and Centre for Quantum Computer and Communication Technology, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia.
Alessandro
A
Fedrizzi
Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia.
Cyril
C
Branciard
Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia and Centre for Quantum Computer and Communication Technology, School of Mathematics and Physics, University of Queensland, Brisbane QLD 4072, Australia.
Andrew G
AG
White