Publications

2006
L Vaidman, N Erez, and A Retzker. 2006. “Another look at quantum teleportation.” International Journal of Quantum Information, 4, 1, Pp. 197-208. Publisher's Version Abstract
A dialog with Asher Peres regarding the meaning of quantum teleportation is briefly reviewed. The Braunstein–Kimble method for teleportation of light is analyzed in the language of quantum wave functions. A pictorial example of continuous variable teleportation is presented using computer simulation.
2005
B Reznik, A Retzker, and J Silman. 4/14/2005. “Violating Bell's inequalities in vacuum.” Physical Review a, 71, 4. Publisher's Version Abstract
We employ an approach wherein the ground state entanglement of a relativistic free scalar field is directly probed in a controlled manner. The approach consists of having a pair of initially nonentangled detectors locally interact with the vacuum for a finite duration T, such that the two detectors remain causally disconnected, and then analyzing the resulting detector mixed state. We show that the correlations between arbitrarily far-apart regions of the vacuum cannot be reproduced by a local hidden-variable model, and that as a function of the distance L between the regions, the entanglement decreases at a slower rate than ∼exp[−(L∕cT)3].
A Retzker, JI Cirac, and B Reznik. 2/9/2005. “Detecting vacuum entanglement in a linear ion trap.” Physical Review Letters, 94, 5. Publisher's Version Abstract
We propose and study a method for detecting ground-state entanglement in a chain of trapped ions. We show that the entanglement between single ions or groups of ions can be swapped to the internal levels of two ions by sending laser pulses that couple the internal and motional degrees of freedom. This allows us to entangle two ions without actually performing gate operations. A proof of principle of the effect can be realized with two trapped ions and is feasible with current technology.
2004
B Reznik, A Retzker, and J Silman. 7/6/2004. “A lower bound on ground state entanglement between two regions for a free field.” Journal of Modern Optics, 51, 6-7, Pp. 833-840. Publisher's Version Abstract
In discrete models, such as spin chains, the entanglement between a pair of particles in a chain has been shown to vanish beyond a certain separation. In the continuum, a quantum field ⊘(x) at a point represents a single degree of freedom, thus at a region of finite size there are infinite separate degrees of freedom. We show that as a consequence, in contrast to discrete models, the ground state of a free, quantized and relativistic field exhibits entanglement between any pair of arbitrarily separated finite regions. We also provide a lower bound on the decay rate of the entanglement as a function of the separation length between the regions and briefly discuss the physical reasons behind this different behaviour of discrete and continuous systems.
2002
A Retzker and B Shapiro. 2/2002. “Infinite range correlations of intensity in random media.” Pramana-Journal of Physics, 58, 2, Pp. 225-231. Publisher's Version Abstract
We study a new type of long-range correlations for waves propagating in a random medium. These correlations originate from scattering events which take place close to a point source. The scattered waves propagate by diffusion to distant regions. In this way long range correlations, between any pair of distant points, are established.