arXiv subjects

Terry Rudolph

Publications and source records attributed to Terry Rudolph.

114 records · Page 7Linked to original sources

arXiv2001

Comment on "The Quantum State of a Propagating Laser Field"

We comment on the theoretical quantum state of a propagating laser field proposed by van Enk and Fuchs [quant-ph/0104036, quant-ph/0111157] and clarify that the multimode description of the propagating laser field does not modify our analysis of continuous variable quantum teleportation [quant-ph/0103147]. Furthermore we point out that the ``complete measurements'' discussed by van Enk and Fuchs have not been achieved by existing technology and may not be possible even in principle.

quant-ph↗

arXiv2001

A simple gate for linear optics quantum computing

We describe a simple scheme for implementing the non-linear sign gate of Knill, Laflamme and Milburn (Nature, {\bf 409}, 46-52, Jan. 4 (2001)) which forms the basis of an experiment underway at the University of Vienna.

quant-ph↗

arXiv2001

Requirement of optical coherence for continuous-variable quantum teleportation

We show that the sender (Alice) and the receiver (Bob) each require coherent devices in order to achieve unconditional continuous variable quantum teleportation (CVQT), and this requirement cannot be achieved with conventional laser sources, even in principle. The appearance of successful CVQT in recent experiments is due to interpreting the measurement record fallaciously in terms of one preferred ensemble (or decomposition) of the correct density matrix describing the state. Our analysis is unrelated to technical problems such as laser phase drift or finite squeezing bandwidth.

quant-ph↗

arXiv1999

Quantum information processing in localized modes of light within a photonic band-gap material

The single photon occupation of a localized field mode within an engineered network of defects in a photonic band-gap (PBG) material is proposed as a unit of quantum information (qubit). Qubit operations are mediated by optically-excited atoms interacting with these localized states of light as the atoms traverse the connected void network of the PBG structure. We describe conditions under which this system can have independent qubits with controllable interactions and very low decoherence, as required for quantum computation.

quant-ph↗

arXiv1999

Quantum Information is physical too

We discuss the physical nature of quantum information, in particular focussing on tasks that are achievable by some physical realizations of qubits but not by others.

quant-ph↗

arXiv1999

Quantum Triangulation and Violation of Conservation of Trouble

A scheme is described that allows Alice to communicate to Bob where on earth she is, even though she doesn't know herself. The situation described shows how the generalization of a recent result of Gisin and Popescu [quant-ph/9901072] could be useful.

quant-ph↗