Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2607.29556

Comparison of Spatial Entanglement between dissociated atom and ion : molecular ion photo-dissociated by sequential two-photon absorption and correlated two-photon absorption

Krishna Rai Dastidar
View original source ↗Read source document ↗Export metadata ↓

Abstract

We have studied the fidelity of spatial entanglement between dissociated atom and ion from two photon dissociation of hydrogen molecular ion H 2 + . Two processes for two photon dissociation of molecular ion have been considered (i) sequential two photon (STP) absorption and (ii) correlated two photon (CTP) absorption by the molecular ion. We compared the results for fidelity of spatial entanglement (FSE) between dissociated atom and ion for these two types of dissociation. In a previous study in our group [1] we have shown that when an atom interact with nonlocal mode of electromagnetic field (which has been derived field theoretically), simultaneous phase-correlated two pho1 ton absorption by the atom occurs within a very short time δt << ω , where ω is the laser frequency, and the rate of this correlated two photon absorption is linear in intensity. This will happen when the photon flux in the interaction region is high i.e. laser intensity is higher than 10 10 W/cm 2 . In this work we have extended this formalism to study the correlated two photon dissociation of molecular ion and to explore the effect of correlation between two simultaneous photo-absorption processes on the fidelity for spatial entanglement of dissociated atom and ion. Dependence of fidelity for spatial entanglement on the photon frequency has been studied for both the STP and CTP dissociation, to show that photon frequency can be used as control parameter to achieve maximum fidelity. Saturation of fidelity with the increase in time at which fidelity was calculated shows the robustness of the processes considered here. A scheme for detection of spatial entanglement between ion and atom has been suggested.

Explore related subjects

quant-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Krishna Rai Dastidar. 2026-08-03. Comparison of Spatial Entanglement between dissociated atom and ion : molecular ion photo-dissociated by sequential two-photon absorption and correlated two-photon absorption. https://arxiv.org/abs/2607.29556

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Fermionic magic resources in disordered quantum spin chains

Fermionic non-Gaussianity quantifies a quantum state's deviation from a classically tractable free-fermionic description, constituting a necessary resource for computational quantum advantage. Here we use fermionic antiflatness (FAF) to measure this deviation across ergodic and many-body localized (MBL) regimes. We focus on the paradigmatic disordered spin-$1\!/2$ XXZ chain and its impurity variant with local interactions. Across highly excited eigenstates, FAF evolves from typical-state behavior at weak disorder to strongly suppressed values deep in the MBL regime, with volume-law scaling in the XXZ chain and an area-law bound in the impurity setting. Rare long-range cat-like eigenstates exhibit a pronounced enhancement of FAF, making it a sensitive diagnostic of mechanisms proposed to destabilize MBL. Starting from product states, we find that in the MBL regime FAF grows slowly in time, approaching saturation via a power-law relaxation. Overall, our results show that MBL suppresses fermionic non-Gaussianity, and the associated complexity beyond free fermions, while ergodicity restores it, motivating explorations of fermionic non-Gaussianity in other ergodicity-breaking phenomena.

quant-ph↗
arXiv2026

Progressive Binarization - Pauli Correlation Encoding: a Continuation Method for Constrained Optimization

Pauli Correlation Encoding (PCE) reduces the qubit requirements of quantum optimization by embedding the problem variables into the expectation values of Pauli observables, so that the number of qubits can be much smaller than the number of variables. PCE has not yet been studied for constrained optimization. We extend it to constrained combinatorial problems, using the budget-constrained MinCut as a case study, and show that the standard formulation fails to reliably enforce the constraint: feasibility hinges on the binarization of the encoded variables, which depends sensitively on hyperparameters that are hard to tune and do not transfer across instances. To address this, we introduce Progressive-Binarization PCE (PB-PCE), an adaptive continuation scheme that progressively increases the binarization parameter while re-optimizing the circuit from the previous solution, driving the variables towards the binary domain. PB-PCE attains near-complete constraint satisfaction (88--100\%) and smaller cut sizes than standard PCE, with a number of stages (10--20) essentially independent of problem size, solving instances of up to 300 variables with only 9-qubit circuits.

quant-ph↗
arXiv2026

A quantum model for synchronizing finite state transition systems

We propose a quantum model for finding a resetting input sequence (RS) which can take a finite state transition system (FA), to particular state independent of its current state. The complexity of finding such sequences for various types of FA can be NP-Hard or even PSPACE-Complete. To this end, we represent the FA states, inputs, and transition function in quantum space. Accordingly, we propose a model to represent the execution of an input sequence of a particular length $l$ starting form an initial FA state. The model is extended considering the application in superposition of all input sequences of length $l$ to an initial state of the FA. The model is further extended considering the application of all input sequences to all initial states of the FA capturing for every input sequence the collection (ordered list) of states reached by applying the sequence to all states of the FA. The amplitude amplification algorithm is then used as it combines similar collections of reached states while preserving all input sequences that reach these collections. A Grover search for a reached collection where its elements correspond to the same FA state provides a RS for the FA. Our approach offers a quadratic gain over the exponential complexity of traditional brute-force method, which is the only method that can be applied to a general FA class.

quant-ph↗