Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Einstein-Podolsky-Rosen-Bohm correlation in photoelectron–Auger-electron coincidence spectroscopy of atoms

Naresh Chandra, R. Ghosh

Published Nov 20, 2006• 16 citations
Publisher

Abstract

We present a theoretical analysis of spin-entanglement between a photoelectron and an Auger electron sequentially ejected from an atom (say, $A$) following the absorption of a single photon. Entanglement, both without and with spin-orbit interaction has been analyzed. In the former case, entanglement in a photo-Auger electron pair is generated only by the electrostatic Coulomb forces inside an atom and completely characterized merely by the multiplicities of the electronic states of $A$, ${A}^{{+}^{*}}$, ${A}^{2+}$ participating in the process, without using any protocols already suggested in the literature for this purpose. The presence of both the Coulomb and spin-orbit interactions, on the other hand, couples the entanglement of this bipartite state with the dynamics and kinematics of the whole process, as well as with the properties of the absorbed photon. In such cases, therefore, it is not possible to predict, a priori, the photo-Auger electron entanglement. These discussions have quantitatively been illustrated by several examples.

DOI
10.1103/physreva.74.052329

Related papers

Entanglement in double photoionization of atoms

Naresh Chandra, M Chakraborty

In this paper, we study the entanglement properties of a pair of electrons ejected simultaneously from an atom following the absorption of a single photon. We show that, in the absence of spin-orbit interaction (SOI), the non-separability of the state of two photoelectrons in a pair depends upon the spins of the atom and of its residual dication. The two electrons produced in a double photoionization experiment may always be entangled, on the other hand, if the SOI is taken into account. In the latter case, entanglement will be affected by, among other things, the photoionization dynamics and the state of polarization of the absorbed radiation.

Journal of Physics B Atomic Molecular and Optical Physics•May 9, 2002•19 citations

Generation of entanglement between spin of an electron and polarization of a photon

Naresh Chandra, R. Ghosh

This paper shows an electron and a photon, emitted in two consecutive steps from an atom following the absorption of a single photon, may be entangled in the presence of the spin-orbit interaction only. This entanglement strongly depends upon the polarization of the absorbed and of the radiated photons, kinematics of two emitted particles, and dynamics of photoionization; however, the photoemission dynamics plays no role in this entanglement. This hybrid entanglement can be used in teleporting a quantum state encoded in a flying/stationary material particle onto a light pulse, or vice versa. Such an electron-photon entanglement, in addition, will make it possible to learn about the polarization of a single photon or spin-polarization of a free electron without making any measurements on the corresponding particle itself.

Quantum Information and Computation•Jan 1, 2009•4 citations

Real-time Entanglement of Auger and XPS-electrons: a preliminary investigation

Philip Johansson

In this work, we employ a semi-classical approach to light matter interaction to describe and char- acterize spin configurations resulting from quantum correlations between electrons created by a photoemission event and by the following Auger decay. The system studied consists of three atomic levels and two continua. Initially, an external classical light field, in the form of a narrow Gaussian packet, perturbs the system, and transfers the density of charge, corresponding to one electron (the photoelectron), from the core level to the continuum. The Auger decay then occurs, whereby an electron from either of the valence levels decay to the core while, at the same time, another electron (the Auger electron) is emitted to the continuum. The description of the system is performed in the time domain, by time-evolving the many-particle wave function. Tracking the density of charge in the atomic levels and the continuum levels allows for a description of the dynamics of photoe- mission and Auger decay. Calculating the concurrence, as measure of entanglement, between the photoelectron and the Auger electron, gives insight about the correlation between their spins. We consider two scenarios; altering the relative strengths of the matrix elements responsible for anti-parallel and parallel spin configuration while keeping the interaction between the photoelectron and the Auger electron fixed, and secondly varying the interaction while keeping all the matrix elements fixed. The effect of increasing the strength of the parallel-spin configuration can be seen in the concurrence decreasing, diminishing the correlation between the spin of the photo- and the Auger electron. Furthermore, we find that the interactions between the electrons in the continuum strongly affect the modality of entanglement. While giving a rather simplistic description of a realistic atomic system, our results support the scope of the model to give valuable conceptual insight, into novel qualitative aspects of the temporal dynamics of the Auger decay.

•Jan 1, 2019•0 citations

Determination of Qubit Entanglement in One-step Double Photoionization of Helium Atom

Minakshi Chakraborty, S. Sen

Quantum entanglement is a unique phenomenon of quantum mechanics that explains how two subatomic particles are correlated even if they are separated by a vast distance. The phenomena of quantum entanglement are useful resources for quantum information. In this chapter, we will study the entanglement properties of bipartite states of two electronic qubits, without observing spin-orbit interaction (SOI), produced by single-step double photoionization in helium atom following the absorption of a single photon. In absence of SOI, Russell-Saunders coupling (L-S coupling) is applicable. We observe that the entanglement depends significantly on the direction of the ejection, as well as the spin quantization of photoelectrons.

IntechOpen eBooks•Aug 27, 2022•1 citation

Entanglement in double photoionization of rotating linear molecules

Naresh Chandra, R. Ghosh

This paper investigates the relationship, if any, which may exist between the electron-electron correlation and spin entanglement of two electrons ejected simultaneously from a linear molecule following the absorption of a single photon. In order to properly learn about the influence of the molecular dynamics on this relationship and also to take into account the parity of the molecular states, double photoionization has been studied by including rotational degrees of freedom in the Hund's coupling schemes (a) and (b). Entanglement properties of the ejected pair of electrons with respect to their spins have been investigated in each of these coupling schemes without or with taking spin dependent interactions into account. The existence, or otherwise, of the entanglement is predicted on the basis of the negativity of the partial transpose of the density matrix calculated for each case considered in this paper.

Physical Review A•Jan 27, 2004•17 citations

Bipartite Entanglement for Two Electronic Qubits in Double Photoionization of Xeon

M. Chakraborty

Objectives: To study of entanglement between two electronic qubits,without observing spin orbit interaction (SOI), produced by double photo ionization from Xeon atom following the absorption of a photon. Methods: In absence of SOI, Russel-Salunders coupling (L-S coupling) is applicable. As the estimations of entanglement we have considered PeresHorodecki condition and negativity. In case of L-Scoupling, all the properties of electronic qubits are predicted merely with the knowledge of the spins of the target atom, the residual photoion, emitted electrons and the state of polarization of the absorbed photon. Findings: We have found that the electronic qubits may be totally entangled, partially entangled or separable depending on spin states of target Xe, residualdication Xe2+,emitted electrons and the state of polarization of incident photon as well as of the direction sspin quantization and ejection of the photoelectrons. Applications/ Improvements: Studies of quantumen tanglement and its paradoxical properties hold the key to various Quantum information (QI) tasks such as quantum teleportation, quantum cryptography and quantum computer technology. Keywords: Density Operator PACS No. 32.30, L-S Coupling, Negativity, Peres-Horodecki Condition

Indian Journal of Science and Technology•Jun 1, 2017•0 citations
We present a theoretical analysis of spin-entanglement between a photoelectron and an Auger electron sequentially ejected from an atom (say, AAA) following the absorption of a single photon. Entanglement, both without and with spin-orbit interaction has been analyzed. In the former case, entanglement in a photo-Auger electron pair is generated only by the electrostatic Coulomb forces inside an atom and completely characterized merely by the multiplicities of the electronic states of AAA, A+∗{A}^{{+}^{*}}A+∗, A2+{A}^{2+}A2+ participating in the process, without using any protocols already suggested in the literature for this purpose. The presence of both the Coulomb and spin-orbit interactions, on the other hand, couples the entanglement of this bipartite state with the dynamics and kinematics of the whole process, as well as with the properties of the absorbed photon. In such cases, therefore, it is not possible to predict, a priori, the photo-Auger electron entanglement. These discussions have quantitatively been illustrated by several examples.
In this paper, we study the entanglement properties of a pair of electrons ejected simultaneously from an atom following the absorption of a single photon. We show that, in the absence of spin-orbit interaction (SOI), the non-separability of the state of two photoelectrons in a pair depends upon the spins of the atom and of its residual dication. The two electrons produced in a double photoionization experiment may always be entangled, on the other hand, if the SOI is taken into account. In the latter case, entanglement will be affected by, among other things, the photoionization dynamics and the state of polarization of the absorbed radiation.
This paper shows an electron and a photon, emitted in two consecutive steps from an atom following the absorption of a single photon, may be entangled in the presence of the spin-orbit interaction only. This entanglement strongly depends upon the polarization of the absorbed and of the radiated photons, kinematics of two emitted particles, and dynamics of photoionization; however, the photoemission dynamics plays no role in this entanglement. This hybrid entanglement can be used in teleporting a quantum state encoded in a flying/stationary material particle onto a light pulse, or vice versa. Such an electron-photon entanglement, in addition, will make it possible to learn about the polarization of a single photon or spin-polarization of a free electron without making any measurements on the corresponding particle itself.
In this work, we employ a semi-classical approach to light matter interaction to describe and char- acterize spin configurations resulting from quantum correlations between electrons created by a photoemission event and by the following Auger decay. The system studied consists of three atomic levels and two continua. Initially, an external classical light field, in the form of a narrow Gaussian packet, perturbs the system, and transfers the density of charge, corresponding to one electron (the photoelectron), from the core level to the continuum. The Auger decay then occurs, whereby an electron from either of the valence levels decay to the core while, at the same time, another electron (the Auger electron) is emitted to the continuum. The description of the system is performed in the time domain, by time-evolving the many-particle wave function. Tracking the density of charge in the atomic levels and the continuum levels allows for a description of the dynamics of photoe- mission and Auger decay. Calculating the concurrence, as measure of entanglement, between the photoelectron and the Auger electron, gives insight about the correlation between their spins. We consider two scenarios; altering the relative strengths of the matrix elements responsible for anti-parallel and parallel spin configuration while keeping the interaction between the photoelectron and the Auger electron fixed, and secondly varying the interaction while keeping all the matrix elements fixed. The effect of increasing the strength of the parallel-spin configuration can be seen in the concurrence decreasing, diminishing the correlation between the spin of the photo- and the Auger electron. Furthermore, we find that the interactions between the electrons in the continuum strongly affect the modality of entanglement. While giving a rather simplistic description of a realistic atomic system, our results support the scope of the model to give valuable conceptual insight, into novel qualitative aspects of the temporal dynamics of the Auger decay.
Quantum entanglement is a unique phenomenon of quantum mechanics that explains how two subatomic particles are correlated even if they are separated by a vast distance. The phenomena of quantum entanglement are useful resources for quantum information. In this chapter, we will study the entanglement properties of bipartite states of two electronic qubits, without observing spin-orbit interaction (SOI), produced by single-step double photoionization in helium atom following the absorption of a single photon. In absence of SOI, Russell-Saunders coupling (L-S coupling) is applicable. We observe that the entanglement depends significantly on the direction of the ejection, as well as the spin quantization of photoelectrons.
This paper investigates the relationship, if any, which may exist between the electron-electron correlation and spin entanglement of two electrons ejected simultaneously from a linear molecule following the absorption of a single photon. In order to properly learn about the influence of the molecular dynamics on this relationship and also to take into account the parity of the molecular states, double photoionization has been studied by including rotational degrees of freedom in the Hund's coupling schemes (a) and (b). Entanglement properties of the ejected pair of electrons with respect to their spins have been investigated in each of these coupling schemes without or with taking spin dependent interactions into account. The existence, or otherwise, of the entanglement is predicted on the basis of the negativity of the partial transpose of the density matrix calculated for each case considered in this paper.
Objectives: To study of entanglement between two electronic qubits,without observing spin orbit interaction (SOI), produced by double photo ionization from Xeon atom following the absorption of a photon. Methods: In absence of SOI, Russel-Salunders coupling (L-S coupling) is applicable. As the estimations of entanglement we have considered PeresHorodecki condition and negativity. In case of L-Scoupling, all the properties of electronic qubits are predicted merely with the knowledge of the spins of the target atom, the residual photoion, emitted electrons and the state of polarization of the absorbed photon. Findings: We have found that the electronic qubits may be totally entangled, partially entangled or separable depending on spin states of target Xe, residualdication Xe2+,emitted electrons and the state of polarization of incident photon as well as of the direction sspin quantization and ejection of the photoelectrons. Applications/ Improvements: Studies of quantumen tanglement and its paradoxical properties hold the key to various Quantum information (QI) tasks such as quantum teleportation, quantum cryptography and quantum computer technology. Keywords: Density Operator PACS No. 32.30, L-S Coupling, Negativity, Peres-Horodecki Condition