TY - JOUR

T1 - Achieving minimum-error discrimination of an arbitrary set of laser-light pulses

AU - Da Silva, Marcus P.

AU - Guha, Saikat

AU - Dutton, Zachary

PY - 2013/5/23

Y1 - 2013/5/23

N2 - Laser light is widely used for communication and sensing applications, so the optimal discrimination of coherent states - the quantum states of light emitted by an ideal laser - has immense practical importance. Due to fundamental limits imposed by quantum mechanics, such discrimination has a finite minimum probability of error. While concrete optical circuits for the optimal discrimination between two coherent states are well known, the generalization to larger sets of coherent states has been challenging. In this paper, we show how to achieve optimal discrimination of any set of coherent states using a resource-efficient quantum computer. Our construction leverages a recent result on discriminating multicopy quantum hypotheses. As illustrative examples, we analyze the performance of discriminating a ternary alphabet and show how the quantum circuit of a receiver designed to discriminate a binary alphabet can be reused in discriminating multimode hypotheses. Finally, we show that our result can be used to achieve the quantum limit on the rate of classical information transmission on a lossy optical channel, which is known to exceed the Shannon rate of all conventional optical receivers.

AB - Laser light is widely used for communication and sensing applications, so the optimal discrimination of coherent states - the quantum states of light emitted by an ideal laser - has immense practical importance. Due to fundamental limits imposed by quantum mechanics, such discrimination has a finite minimum probability of error. While concrete optical circuits for the optimal discrimination between two coherent states are well known, the generalization to larger sets of coherent states has been challenging. In this paper, we show how to achieve optimal discrimination of any set of coherent states using a resource-efficient quantum computer. Our construction leverages a recent result on discriminating multicopy quantum hypotheses. As illustrative examples, we analyze the performance of discriminating a ternary alphabet and show how the quantum circuit of a receiver designed to discriminate a binary alphabet can be reused in discriminating multimode hypotheses. Finally, we show that our result can be used to achieve the quantum limit on the rate of classical information transmission on a lossy optical channel, which is known to exceed the Shannon rate of all conventional optical receivers.

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U2 - 10.1103/PhysRevA.87.052320

DO - 10.1103/PhysRevA.87.052320

M3 - Article

AN - SCOPUS:84878490475

SN - 1050-2947

VL - 87

JO - Physical Review A - Atomic, Molecular, and Optical Physics

JF - Physical Review A - Atomic, Molecular, and Optical Physics

IS - 5

M1 - 052320

ER -