Entanglement-based linear-optical qubit amplifier
Abstract
We propose a linear-optical scheme for an efficient amplification of a photonic qubit based on interaction of the signal mode with a pair of entangled ancillae. In contrast to a previous proposal for qubit amplifier by Gisin [Phys Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.105.070501 105, 070501 (2010)], the success probability of our device does not decrease asymptotically to zero with increasing gain. Moreover, we show how the device can be used to restore entanglement deteriorated by transmission over a lossy channel and calculate the secure key rate for device-independent quantum key distribution.
- Publication:
-
Physical Review A
- Pub Date:
- July 2013
- DOI:
- arXiv:
- arXiv:1306.1342
- Bibcode:
- 2013PhRvA..88a2327M
- Keywords:
-
- 03.67.Hk;
- 42.50.Dv;
- 03.67.Lx;
- Quantum communication;
- Nonclassical states of the electromagnetic field including entangled photon states;
- quantum state engineering and measurements;
- Quantum computation;
- Quantum Physics
- E-Print:
- 7 pages, 7 figures