Si-Hui Tan

Learn More
An important practical open question has been to design explicit, structured optical receivers that achieve the Holevo limit in the contexts of optical communication and “quantum reading.” The Holevo limit is an achievable rate that is higher than the Shannon limit of any known optical receiver. We demonstrate how a sequential decoding(More)
An optical transmitter irradiates a target region containing a bright thermal-noise bath in which a low-reflectivity object might be embedded. The light received from this region is used to decide whether the object is present or absent. The performance achieved using a coherent-state transmitter is compared with that of a quantum-illumination transmitter,(More)
Encryption schemes often derive their power from the properties of the underlying algebra on the symbols used. Inspired by group theoretic tools, we use the centralizer of a subgroup of operations to present a private-key quantum homomorphic encryption scheme that enables a broad class of quantum computation on encrypted data. The quantum data is encoded on(More)
Encryption schemes often derive their power from the properties of the underlying algebra on the symbols used. Inspired by group theoretic tools, we use the centralizer of the group of unitary operations to present a private-key quantum homomorphic encryption scheme that hides arbitrary quantum computations. A particular instance of our encoding hides(More)
We derive the quantum limit on the error probability exponent for discriminating any M multimode coherent states of light and show that it is four times that of an ideal heterodyne receiver for the same signal set. We then propose a receiver that achieves the quantum limit using auxiliary coherent-state fields, beam splitters, and single-photon detectors.(More)
Discriminating coherent states of light is an important instance of quantum state discrimination that is central to all applications of laser light. We obtain the ultimate quantum limit on the error probability exponent for discriminating among any M multimode coherent-state signals via the recently developed theory of the quantum Chernoff exponent in M-ary(More)
The conditions for a quantum measurement to discriminate a set of states with the minimum probability of error were specified by Yuen, Kennedy and Lax, and are often termed the YKL conditions [1]. Since light is quantum mechanical, the ultimate limit on minimum-error discrimination of an optical modulation constellation is determined by the YKL bound.(More)
  • 1