11 Result(s)
within
S. S. Nazin
English
Biological and Medical Physics, Biophysics
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Article
The role of causality in ensuring the ultimate security of relativistic quantum cryptography
One of the central points of quantum information theory is the problem of ultimate security of quantum cryptography; i.e., the security that is due only to the fundamental laws of nature rather than to technic...
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Article
Quantum bit commitment in a channel with noise
Under rather general assumptions about the properties of a quantum channel with noise, a quantum protocol providing implementation of secret bit commitment with the probability as close to unity as is wished i...
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Article
Relativistic quantum coin tossing
A relativistic quantum exchange protocol enabling “coin tossing at a distance” between two participants is proposed. The exchange protocol is based on the fact that to distinguish a pair of orthogonal states w...
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Article
The Einstein-Podolsky-Rosen effect and causality
It is shown for a simple example that the formalism of quantum field theory and the requirement of microcausality do not forbid complete correlation of the results of measurements performed by two observers se...
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Article
Measurement of the state of an individual spin using a “turnstile”
A scheme is proposed for measuring the state of an individual spin (system of spins). The scheme is based on the idea of a single-electron “turnstile” and the injection of single spin-polarized electrons from ...
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Article
Nonstationary-states quantum cryptography
A quantum cryptosystem is proposed in which a pair of nonstationary states differing in their times of preparation is used as the information carriers.
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Article
Quantum cryptography based on homodyne detection (vacuum-state cryptosystem)
A new protocol is proposed for quantum cryptography. The protocol is based on the use of a set of measurements which make it possible to reconstruct completely the density matrix — the information carrier — of...
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Article
Is there a fundamental limit on the length of a communication channel in a single-photon quantum cryptosystem?
It is shown that there is no formal limit on the length of the communication channel in a single-photon quantum cryptosystem with arbitrary dispersion if there is no dam** in the communication line. A prescr...
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Article
Quantum cryptography based on the energy-time uncertainty relation
A new quantum cryptosystem based on the energy-time uncertainty relation is proposed. This cryptosystem can be implemented with both biphotonic states and single photons.
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Article
Macroscopic quantum tunneling in small magnetic particles
Macroscopic quantum tunneling of magnetization in small antiferromagnetic clusters is studied for the spin-1/2 anisotropic (J z ≡ J, J x =J ...
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Article
Quantum cryptography based on quantum dots
Network protocols are formulated for the phase-coding and correlated-photon-pairs quantum cryptosystems. These protocols are free of the restriction imposed on the distance between the two legitimate users by ...
