21 citations · 33 across the 2 of their papers we have counts for
5 papers
Security of quantum key distribution with discrete rotational symmetry
Masato Koashi
We prove the unconditional security of quantum key distribution protocols using attenuated laser pulses with M different linear polarizations. When M=4, the proof covers the so-cal…
Simple security proof of quantum key distribution via uncertainty principle
Masato Koashi
We present an approach to the unconditional security of quantum key distribution protocols based on the uncertainty principle. The approach applies to every case that has been trea…
Maximum entanglement of quantum-dot systems with single excitation in the spin van der Waals model
A. Miranowicz, S. K. Ozdemir, M. Koashi +2
Time evolution of entanglement of N quantum dots is analyzed within the spin-1/2 van der Waals (or Lipkin-Meshkov-Glick) XY model. It is shown that, for a single dot initially exci…
Teleportation cost and hybrid compression of quantum signals
Masato Koashi, Nobuyuki Imoto
The amount of entanglement necessary to teleport quantum states drawn from general ensemble is derived. The case of perfect transmission of individual states and that…
What is Possible Without Disturbing Partially Known Quantum States?
Masato Koashi, Nobuyuki Imoto
Consider a situation in which a quantum system is secretly prepared in a state chosen from the known set of states. We present a principle that gives a definite distinction between…