432 citations · 730 across the 5 of their papers we have counts for
5 papers
Two qubit copying machine for economical quantum eavesdropping
Chi-Sheng Niu, Robert B. Griffiths
We study the mapping which occurs when a single qubit in an arbitrary state interacts with another qubit in a given, fixed state resulting in some unitary transformation on the two…
Optimal Copying of One Quantum Bit
Chi-Sheng Niu, Robert B. Griffiths
A quantum copying machine producing two (in general non-identical) copies of an arbitrary input state of a two-dimensional Hilbert space (qubit) is studied using a quality measure…
Optimal Eavesdropping in Quantum Cryptography. II. Quantum Circuit
Robert B. Griffiths, Chi-Sheng Niu
It is shown that the optimum strategy of the eavesdropper, as described in the preceding paper, can be expressed in terms of a quantum circuit in a way which makes it obvious why c…
Optimal Eavesdropping in Quantum Cryptography. I
Christopher A. Fuchs, Nicolas Gisin, Robert B. Griffiths +2
We consider the Bennett-Brassard cryptographic scheme, which uses two conjugate quantum bases. An eavesdropper who attempts to obtain information on qubits sent in one of the bases…
Semiclassical Fourier Transform for Quantum Computation
Robert B. Griffiths, Chi-Sheng Niu
Shor's algorithms for factorization and discrete logarithms on a quantum computer employ Fourier transforms preceding a final measurement. It is shown that such a Fourier transform…