Relativistically covariant state-dependent cloning of photons
arXiv:0705.4291 · doi:10.1103/PhysRevA.77.042302
Abstract
The influence of the relativistic covariance requirement on the optimality of the symmetric state-dependent 1 -> 2 cloning machine is studied. Namely, given a photonic qubit whose basis is formed from the momentum-helicity eigenstates, the change to the optimal cloning fidelity is calculated taking into account the Lorentz covariance unitarily represented by Wigner's little group. To pinpoint some of the interesting results, we found states for which the optimal fidelity of the cloning process drops to 2/3 which corresponds to the fidelity of the optimal classical cloner. Also, an implication for the security of the BB84 protocol is analyzed.
arXiv commentcorrected, rewritten and accepted in PRA
References in corpus (18)
- Black holes as mirrors: quantum information in random subsystems
- Quantum Copying: Beyond the No-Cloning Theorem
- Optimal Quantum Cloning Machines
- Quantum Information and Relativity Theory
- Quantum cloning
- Optimal Universal and State-Dependent Quantum Cloning
- Quantum Entanglement of Moving Bodies
- Phase covariant quantum cloning
- Spin flips and quantum information for anti-parallel spins
- Einstein-Podolsky-Rosen-Bohm experiment with relativistic massive particles
- Relativistic Einstein-Podolsky-Rosen correlation and Bell's inequality
- Optimal Non-Universally Covariant Cloning
- Relativistically invariant quantum information
- Entangled Light in Moving Frames
- Relativistic Doppler effect in quantum communication
- Photon polarization and Wigner's little group
- Intrinsic Entanglement Degradation by Multi-Mode Detection
- The effect of focusing on polarization qubits