Southwest Quantum Information and Technology

Distinguishability of qubit and qutrit Bell states with projective and non-projective linear measurement

Presenting Author: Nathaniel Leslie, Harvey Mudd College
Contributing Author(s): Julien Devin and Theresa W. Lynn

We present new maximal distinguishability limits for qudit Bell states with projective and non-projective linear evolution and local measurement (LELM) devices. A well-known no-go theorem establishes that projective LELM detection schemes cannot reliably distinguish all four qubit Bell states; they can only reliably distinguish three. We show that only 3 out of 9 qutrit Bell states can be distinguished with projective LELM measurements. We also consider the case of non-projective measurements, and show that even general POVM-based LELM measurements cannot reliably distinguish all four qubit Bell states. We also establish that no more than 2d qudit Bell states may be distinguishable with general LELM measurements and in the qutrit case, at most 5 may be distinguishable.

(Session 5 : Thursday from 5:00pm - 7:00pm)