Recent results forentanglement purification with imperfect local operations and measurements are revisited and applied to the quantum repeater problem. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
In quantum communication via noisy channels, the error probability scales exponentially with the length of the channel. We present a scheme of a quantum repeater that overcomes this limitation. The central idea is to connect a string of (imperfect) entangled pairs of particles by using a novel nested purification protocol, thereby creating a single distant pair of high fidelity. Our scheme tolerates general errors on the percent level, it works with a polynomial overhead in time and a logarithmic overhead in the number of particles that need to be controlled locally.
The aim of this paper is to give a review of some recent results concerning the problem of constructing and studying time evolution for quantum systems with infinitely many degrees of freedom. The first rigorous results in this direction are due to O. E. Lanford and D. W. Robinson [17–20], see also [13], Ch. 5.3. An approach to this problem has been proposed by O. Bratteli and D. W. Robinson [12], see also [13], Ch. 6.3. Among recent papers we refer to [1–3], [10–11], [16], [24]. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.