X-Ray photoemission (XPS) spectra, which have been used for analyzing the chemical and nano structural characteristics of thin film- gate dielectric of nano devices and optoelectronic devices, need to be studied with considering the Quantum entanglement between photoelectron (pe) and emitted X-ray photon (ph) as an indication of the quantum technology. In the present work, as an innovation in the quantum technology, a three-electron S-P model consisting of a 1s orbital in the inner shell and a XPS 2p3/2, 2p1/2) orbital in the outer shell by writing the wave function and second quantization - based on creation and annihilation operators. Regarding the pe-ph entanglement (PPE) via an optical selection rule, we found that the linear polarization of emitted X-ray photons; ph, to pe (or pe-ph) entanglement transfer, reveled in reduced density matrix in von Neumann approach can be useful equation for exploring PPE transfers and for applications to nano chip devices.
X-Ray photoemission (XPS) spectra, which have been used for analyzing the chemical and nano structural characteristics of thin film- gate dielectric of nano devices and optoelectronic devices, need to be studied with considering the Quantum entanglement between photoelectron (pe) and emitted X-ray photon (ph) as an indication of the quantum technology. In the present work, as an innovation in the quantum technology, a three-electron S-P model consisting of a 1s orbital in the inner shell and a XPS 2p3/2, 2p1/2) orbital in the outer shell by writing the wave function and second quantization - based on creation and annihilation operators. Regarding the pe-ph entanglement (PPE) via an optical selection rule, we found that the linear polarization of emitted X-ray photons; ph, to pe (or pe-ph) entanglement transfer, reveled in reduced density matrix in von Neumann approach can be useful equation for exploring PPE transfers and for applications to nano chip devices.
We have theoretically investigated the character of entanglement between photoelectrons and emitted X-ray photons in XEPECS process which is a coincidence spectroscopy of photoelectrons and emitted X-ray photons. In the calculations, we used a three-electron sp-model consisting of an inner-shell 1s orbital and an outer-shell 2p orbital. We found that entanglement occurs between spin of photoelectrons and linear polarization of emitted X-ray photons, using the wavefunction of the whole system including the photon as well as the electron system. Furthermore, we calculated the degree of entanglement and found that it shows maximum at a particular angle of emitted X-ray photon.
We theoretically investigated how the quantum entanglement between the spin of the photoelectron and the polarization of the emitted X-ray photon depends on the excited core-level, using the 3$d\rightarrow\ 2p$ and 3$d\rightarrow\ 3p$ SPR-XEPECS (spin- and polarization-resolved XEPECS) processes for Ti2O3-type system, and the 4$f\rightarrow\ 4d$ SPR-XEPECS process for CeF3-type system. In the calculation for Ti2O3-type system, we used TiO6 cluster model with the full-multiplet structure of the Ti ion and the charge-transfer effect between Ti 3d and ligand O 2p orbitals. For CeF3-type system, we used ionic model with the full-multiplet structure of the Ce ion. We found two distinct mechanisms for entanglement generation in the 3$d\rightarrow\ 2p$ and 4$f\rightarrow\ 4d$ cases. The first is generated by the spin-orbit interaction of the 2p core electron, whereas the second is generated by the spin-orbit interaction of the 4f valence electron and strong exchange interaction between the 4f and 4d electrons. However, in the 3$d\rightarrow\ 3p$ case with the strong 3$d-3p$ exchange interaction, we found that the entanglement is not generated due to the crystal field effect. These results reveal the existence of two distinct mechanisms for entanglement generation in X-ray inner-shell excitation processes.
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.
An accessible tabletop source for the production of entangled x rays is crucial for the field of high-energy quantum optics. Here, we present a detailed analysis of the entanglement and polarization of the two photons emitted by an electron in an intense laser wave (nonlinear double-Compton scattering), by working within the framework of strong-field QED. By identifying contributions to the emission probability stemming from the electron being either on-shell or off-shell between the two-photon emissions, we show that the entangled photons are generated via the off-shell contribution for moderate beam energies, which are realizable on a tabletop setup. We propose an experiment to produce and isolate pairs of entangled x rays, through spectral filtering.
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
With progress toward more compact quantum computing architectures, fundamental questions regarding the entanglement of indistinguishable particles need to be addressed. In a solid state device, this quest is naturally connected to the quantum correlations of electrons. Here, we analyze the formation of orbital (mode) and particle entanglement in strongly correlated materials due to the Coulomb interaction between the electrons. We extend the analysis to include spectroscopic measurements of the electronic structure, with a particular focus on the photoemission process. To study the role of the different forms of electronic entanglement, including the effect of particle-number superselection rules, we propose and analyze three different electronic teleportation schemes: quantum teleportation within (i) a molecule on graphene, (ii) a nitrogen-vacancy center, and (iii) a quantum dot array.