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Angular- or $k$-resolved photoelectron spectroscopy in the soft X-ray range gives access to the bulk electronic structure of materials. Here this technique is extended to the spin degree of freedom. A non-magnetic material (tungsten) was…

We report on a method for optimizing the collection of entangled photon pairs in type-II parametric fluorescence. With this technique, we detected 360000 polarization-entangled photon pairs per second in the near-IR region in single-mode…

Quantum Physics · Physics 2009-11-07 Christian Kurtsiefer , Markus Oberparleiter , Harald Weinfurter

We study the polarization characteristics of x-ray photons scattered by hydrogenic atoms, based on the Dirac equation and second-order perturbation theory. The relativistic states used in calculations are obtained using the finite basis set…

Atomic Physics · Physics 2014-10-23 Laleh Safari , Jose Paulo Santos , Pedro Amaro , Filippo Fratini

We consider a model for describing a QED system consisting of a photon beam interacting with quantized charged spinless particles. We restrict ourselves by a photon beam that consists of photons with two different momenta moving in the same…

Quantum Physics · Physics 2022-08-17 A. I. Breev , D. M. Gitman

Using a spontaneous-downconversion photon source, we produce true non-maximally entangled states, i.e., without the need for post-selection. The degree and phase of entanglement are readily tunable, and are characterized both by a standard…

Quantum Physics · Physics 2009-10-31 Andrew G. White , Daniel F. V. James , Philippe H. Eberhard , Paul G. Kwiat

A solid-state approach for quantum networks is advantages, as it allows the integration of nanophotonics to enhance the photon emission and the utilization of weakly coupled nuclear spins for long-lived storage. Silicon carbide,…

The accurate and efficient detection of quantum entanglement remains a central challenge in quantum information science. In this work, we study the detection of entanglement of polarized photons for measurement devices that are solely…

Quantum Physics · Physics 2025-12-19 Marlene Funck , Ilija Funk , Tizian Schmidt , René Schwonnek

In the present work we explore a suitable coarse graining channel as a tool to describe the effective entanglement spreading in a coarse-grained spin-chain with different degrees of resolution. Comparing it with the experimental…

Quantum Physics · Physics 2019-09-04 Pedro Silva Correia , Fernando de Melo

We propose a novel approach to measure spin polarization of nucleons produced in electron--positron collisions. Using existing tracking devices and supporting structure material, general-purpose spectrometers can be utilized as a…

High Energy Physics - Phenomenology · Physics 2025-01-07 Yu-Tie Liang , Xiao-Rong Lv , Andrzej Kupsc , Boxing Gou , Hai-Bo Li

Polarization holonomy is analytically determined for maximally entangled photon pairs that transit a class of closed trajectories in the Kerr metric. This is used to define and investigate an entanglement holonomy not associated with…

General Relativity and Quantum Cosmology · Physics 2024-08-07 Mark T. Lusk

We study polarization squeezing of a light beam initially in the coherent state using the nonlinear interaction hamiltonian $ H=k\big(\hat a_{x}^{\dagger2}+{\hat a_{x}}^2\big)$. For the degree of polarization squeezing, we use a definition…

Quantum Physics · Physics 2016-11-03 Namrata Shukla , Ranjana Prakash

A nonclassical feature of the fourth-order interference at a beam splitter, that genuine photon spin singlets are emitted in predetermined directions even when incident photons are unpolarized, has been used in a proposal for an experiment…

Quantum Physics · Physics 2009-10-31 Mladen Pavicic

Recent theoretical and experiments have explored the use of entangled photons as a spectroscopic probe of material systems. We develop here a theoretical description for entropy production in the scattering of an entangled biphoton state…

Quantum Physics · Physics 2019-05-22 Hao Li , Andrei Piryatinski , Ajay Ram Srimath Kandada , Carlos Silva , Eric R. Bittner

We present two hyperentanglement concentration schemes for two-photon states that are partially entangled in the polarization and time-bin degrees of freedom. The first scheme distills a maximally hyperentangled state from two identical…

Quantum Physics · Physics 2015-04-15 Xihan Li , Shohini Ghose

We use a single trapped 40Ca+ ion as a resonant, polarization-sensitive absorber to detect and characterize the entanglement of tunable narrowband photon pairs from a spontaneous parametric down-conversion source. Single-photon absorption…

Quantum Physics · Physics 2013-04-22 J. Huwer , J. Ghosh , N. Piro , M. Schug , F. Dubin , J. Eschner

How can one detect entanglement between multiple optical paths sharing a single photon? We address this question by proposing a scalable protocol, which only uses local measurements where single photon detection is combined with small…

We investigate entanglement transfer from a system of two spin-entangled electron-hole pairs, each placed in a separate single mode cavity, to the photons emitted during their recombination process. Dipole selection rules and a splitting…

Mesoscale and Nanoscale Physics · Physics 2010-06-24 Jan C. Budich , Bjoern Trauzettel

The present theoretical status of spin-dependent parton densities Delta f^{\gamma}(x,Q^2) of circularly polarized photons is briefly reviewed. It is then demonstrated that measurements of the deep-inelastic spin asymmetry A_1^{\gamma}\simeq…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Stratmann

The polarization analysis of quantized probe light transmitted through an atomic ensemble has been used to prepare entangled collective atomic states. In a "balanced" detection configuration, where the difference signal from two detection…

Quantum Physics · Physics 2009-11-11 C. Genes P. R. Berman

A rather general method for determining the spin density matrix of a multi-particle system from angular decay data is presented. The method is based on a Bloch parameterisation of the $d$-dimensional generalised Gell-Mann representation of…

Quantum Physics · Physics 2026-03-11 Rachel Ashby-Pickering , Alan J. Barr , Agnieszka Wierzchucka