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Related papers: Conditioned Unitary Transformation on biphotons

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The entanglement transfer from electrons localized in a pair of quantum dots to circularly polarized photons is governed by optical selection rules, enforced by conservation of angular momentum. We point out that the transfer can not be…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Titov , B. Trauzettel , B. Michaelis , C. W. J. Beenakker

The polarization of light is critical in various applications, including quantum communication, where the photon polarization encoding a qubit can undergo uncontrolled changes when transmitted through optical fibers. Bends in the fiber,…

Quantum Physics · Physics 2025-06-03 Niklas Braband , Arman Mansouri , Riza Fazili , Stefanie Czischek , Jeff S. Lundeen

We investigate, both theoretically and experimentally, the phenomenon of polarization rotation of a weak, linearly-polarized optical (probe) field in an atomic system with multiple three-level electromagnetically induced transparency (EIT)…

Quantum Physics · Physics 2009-11-13 Shujing Li , Bo Wang , Xudong Yang , Yanxu Han , Hai Wang , Min Xiao , K. C. Peng

We describe a scheme for producing conditional nonlinear phase shifts on two-photon optical fields using an interaction with one or more ancilla two-level atomic systems. The conditional field state transformations are induced by using high…

Quantum Physics · Physics 2007-05-23 A. Gilchrist , G. J. Milburn

A silicon quantum photonic circuit was proposed and demonstrated as an integrated quantum light source for telecom band polarization entangled Bell state generation and dynamical manipulation. Biphoton states were firstly generated in four…

Quantum Physics · Physics 2021-03-16 Dongning Liu , Jingyuan Zheng , Lingjie Yu , Xue Feng , Fang Liu , Kaiyu Cui , Yidong Huang , Wei Zhang

A two-photon process leading to coherent transitions between the two circularly polarized exciton states in a quantum dot is studied. It is shown that optical flipping of the exciton polarization is possible with picosecond laser pulses.…

Mesoscale and Nanoscale Physics · Physics 2007-10-24 P. Machnikowski

Many optically active systems possess spatially asymmetric electron orbitals. These generate permanent dipole moments, which can be stronger than the corresponding transition dipole moments, significantly affecting the system dynamics and…

Quantum Physics · Physics 2023-04-21 Adam Burgess , Marian Florescu , Dominic Michael Rouse

We provide a general approach for the analysis of optical state evolution under conditional measurement schemes, and identify the necessary and sufficient conditions for such schemes to simulate unitary evolution on the freely propagating…

Quantum Physics · Physics 2010-04-09 G. G. Lapaire , Pieter Kok , Jonathan P. Dowling , J. E. Sipe

Entangled photons can be generated "on demand" in a novel scheme involving unitary time reordering of the photons emitted in a radiative decay cascade. The scheme yields polarization entangled photon pairs, even though prior to reordering…

Quantum Physics · Physics 2009-11-13 J. E. Avron , G. Bisker , D. Gershoni , N. H. Lindner , E. A. Meirom , R. J. Warburton

We describe a protocol capable of preparing an arbitrary state of two photons in several spatial modes using pairs of photons generated by spontaneous parametric down-conversion, linear optical elements and single-photon detectors or…

Quantum Physics · Physics 2009-11-13 Karel Lemr , Jaromir Fiurasek

We describe a new experimental approach to probabilistic atom-photon (signal) entanglement. Two qubit states are encoded as orthogonal collective spin excitations of an unpolarized atomic ensemble. After a programmable delay, the atomic…

We construct an entangled photon polarimeter capable of monitoring a two-qubit quantum state in real time. Using this polarimeter, we record a nine frames-per-second video of a two-photon state's transition from separability to…

Quantum Physics · Physics 2015-05-30 Joseph B. Altepeter , Neal N. Oza , Milja Medic , Evan R. Jeffrey , Prem Kumar

We present an experimental implementation of optimum measurements for quantum state discrimination. Optimum maximum-confidence discrimination and optimum unambiguous discrimination of two mixed single-photon polarization states were…

We report on experimental implementation of the optimal universal asymmetric 1->2 quantum cloning machine for qubits encoded into polarization states of single photons. Our linear optical machine performs asymmetric cloning by partially…

Quantum Physics · Physics 2015-05-14 Antonin Cernoch , Jan Soubusta , Lucie Celechovska , Miloslav Dusek , Jaromir Fiurasek

Emission of photon pairs by metal-dielectric interface in case of a superluminally propagating laser-induced nonlinear polarization is considered. Using oblique incidence of the laser wave it is possible to tune frequencies of generated…

Mesoscale and Nanoscale Physics · Physics 2014-05-15 Vladimir Hizhnyakov

In this work we propose a probabilistic method which allows an unambiguous modification of two non-orthogonal quantum states. We experimentally implement this protocol by using two-photon polarization states generated in the process of…

Quantum Physics · Physics 2009-04-27 F. A. Torres-Ruiz , J. Aguirre , A. Delgado , L. Neves , G. Lima , S. Pádua , L. Roa , C. Saavedra

We propose a technique for performing quantum state tomography of photonic polarization-encoded multi-qubit states. Our method uses a single rotating wave plate, a polarizing beam splitter and two photon-counting detectors per photon mode.…

Quantum Physics · Physics 2013-01-18 Mohammadreza Mohammadi , Agata M. Branczyk , Daniel F. V. James

We propose a realization of quantum computing using polarized photons. The information is coded in two polarization directions of the photons and two-qubit operations are done using conditional Faraday effect. We investigate the performance…

Quantum Physics · Physics 2007-05-23 P. Torma , S. Stenholm

We show how Bell observables on a bipartite quantum system can be obtained by local observables via a controlled-unitary transformation. For continuous variables this result holds for the Bell observable corresponding to the…

Quantum Physics · Physics 2007-05-23 Giacomo Mauro D'Ariano , Paolo Perinotti

We report on the experimental implementation of a polarimeter based on a scheme known to be optimal for obtaining the polarization vector of ensembles of spin-1/2 quantum systems, and the alignment procedure for this polarimeter is…

Quantum Physics · Physics 2007-05-23 Alexander Ling , Soh Kee Pang , Antia Lamas-Linares , Christian Kurtsiefer