Ground State Energy Levels Research Articles

Benchmarking the optimization of optical machines with the planted solutions

This research focuses on developing effective benchmarks for quadratic unconstrained binary optimization instances, crucial for evaluating the performance of Ising hardware and solvers. Currently, the field lacks accessible and reproducible models for systematically testing such systems, particularly in terms of detailed phase space characterization. Here, we introduce universal generative models based on an extension of Hebb’s rule of associative memory with asymmetric pattern weights. We conduct comprehensive calculations across different scales and dynamical equations, examining outcomes like the probabilities of reaching the ground state, planted state, spurious state, or other energy levels. Additionally, the generated problems reveal properties such as the easy-hard-easy complexity transition and complex solution cluster structures. This method offers a promising platform for analyzing and understanding the behavior of physical hardware and its simulations, contributing to future advancements in optimization technologies.

Screening the structural, optoelectronic and thermoelectric features of novel inverse perovskites X3MgNa (X= Cl, Br and I): A theoretical investigation

The structural, optoelectronic, and transport features of novel X3MgNa (X = Cl, Br, and I) antiperovskites compounds are revealed by using the density functional theory. The structural stability of all of the compounds under consideration has been verified by using the Birch-Murnaghan equations of states, which indicate that all compounds have structural stability due to ground-state energy levels being negative. The electronic band structure and TDOS results reveal that the electronic band gap of Cl3MgNa is 4.22 eV, Br3MgNa is 2.18 eV, and I3MgNa is zero eV. The partial density of state PDOS results demonstrate that the formation of the conduction and valence bands is due to the hybridization of Cl-3p, Br-4p, Na-3p, and I-5p states. In terms of optical results, reverse perovskite with Br as a cation has shown much better optical conductivity in the ultraviolet range. Therefore, Br3MgNa is a potential candidate among all the compounds for optoelectronic-based applications. The Boltztrap code, which is patched with WEIN2K code, has been used to compute the thermoelectric characteristics of the examined compounds. Br3MgNa has a greater power factor, a high electrical conductivity, and a figure-of-merit; ZT approaches unity, indicating a promising option for thermoelectric applications.

Analytical solution and spectral structure of the two-photon anisotropic Rabi-Stark model

Since the realization of the strong coupling between light and matter in experimental setups, the quantum Rabi model and its generalized models describing the interaction between the boson field and the two-level system have attracted extensive interest again. The study of anisotropic generalized Rabi models enables us to better understand the novel physical properties of the interaction between light and matter in the ultra-strong and deep-strong coupling regions. In this work, the two-photon anisotropic Rabi-Stark model (tpARSM) is analytically solved by using the Bogoliubov operator approach and the su(1, 1) Lie algebra. We derive the G-function, whose zeros give the regular spectrum of the system. By studying the pole structure of the G-function and the coefficients in the function, exceptional solutions, including the first-order quantum phase transition points, doubly degenerate exceptional solutions and nondegenerate exceptional solutions, are obtained. By discussing the spectral structure, we give the conditions for the first-order quantum phase transition of tpARSM. Furthermore, we find that the property that all of the lowest doubly degenerate crossing points in the two-photon Rabi-Stark model have the same energy only holds for the special case of the tpARSM in which the anisotropy parameter is equal to 1. Finally, from the perspective of first-order quantum phase transitions, concise conditions for the ground state energy level to collapse to or escape from the collapse point for the tpARSM are presented. A good understanding of the tpARSM will lay a good foundation for studying the extended two-photon systems involving multiple levels and multiple bosonic modes, and even the relevant open quantum systems.

Crystal structure and luminescence properties of a novel near-infrared phosphor LiAlO2:Fe3+

Cr3+-free near-infrared (NIR) phosphors are currently gaining significant attention in various application fields. A novel Fe3+-activated LiAlO2 NIR phosphor was successfully synthesized by high-temperature solid-state method. Under excitation of 391 nm and 467 nm, the phosphor emits near-infrared light with wavelengths ranging from 600 to 850 nm. The emission bands with peaks at 725 nm correspond to the transition from 4T1(4G) to the ground state energy level 6A1(6S). The optical band gap of LiAlO2 was calculated using Density Function Theory (DFT) and diffuse reflectance spectrum, respectively. The thermal stability of the sample was measured under 391 nm and 467 nm excitation, showing that the emission intensity at 413 K is 55.3 % and 52.4 % of the emission intensity at room temperature.

Topological defects on relativistic quantum oscillator in wormhole space–time background

In this research work, the relativistic quantum dynamics of oscillator field in wormhole background with a topological defect produced by a cosmic string is investigated. We consider an example of Morris–Thorne-type wormhole including a osmic string and derived the wave equation of the relativistic quantum oscillator. Through the Heun equation, we solve analytically the radial equation and obtain the ground state energy level [Formula: see text] and the radial wave function [Formula: see text] as particular cases. In fact, it is shown that the eigenvalue solution of the oscillator field is influenced by the topological defect of cosmic string and shifted the result. Furthermore, the wormhole throat radius also modifies the energy levels and the wave function of the relativistic quantum oscillator.

Effects of [formula omitted]-dimensional circularly symmetric and static traversable wormhole with cosmic string on oscillator field

In this study, we examine the relativistic quantum dynamics of an oscillator field described by the Klein–Gordon equation in a circularly symmetric and static (1+2)-dimensional traversable wormhole space–time with cosmic strings. We derive the radial equation for the Klein–Gordon oscillator in this wormhole background and solved it using special functions. For specific cases, we present the ground state energy level E1,ℓ± and wave function ψ1,ℓ of the oscillator field, subject to a constraint on the oscillator frequency ω1,ℓ. In fact, it is shown that the eigenvalue solution of the oscillator field is influenced by both the cosmic string parameter α and the wormhole throat radius a, leading to shifts in the energy levels and wave functions.

Synthesis, optical, electrochemical, and computational investigation of new cyanopyridine-centered organic dyads

Herein we report the molecular design, synthesis, and inclusive investigation of four novel di-anchored symmetric dyes (CP1-4) centered on electron deficient cyanopyridine scaffold as possible photosensitizers for DSSC application. These new chromogens (CP1-4) comprise a powerful electron-withdrawing cyanopyridine moiety linked with additional electron attracting functionalities such as cyanoacetic acid (CP1), 3-(carboxymethyl) rhodanine (CP2), 2,4,6-pyrimidinetrione (CP3), and 2,6-dihydroxy-2-mercaptopyrimidine (CP4), as effective acceptor/anchoring units via biphenyl donor units. Their in-depth optical and electrochemical behaviour were investigated to assess their suitability as photosensitizers. Further, the molecular modeling calculations were undertaken to understand their ground state properties and energy level potentials. The comprehensive studies revealed that they own all the requisites to performance as a potential photosensitizer for DSSC application.

Near-Field Sensing of Microwave Magnetic Field Phase Difference Enabled by N - V -Center Spins

Sensing microwave (MW) fields through a quantum protocol has attracted increasing interest, and the phase of MW fields is an essential parameter in communication and quantum technologies. This work proposes a quantum-effect-based method for measuring the phase difference of MW magnetic fields under near-field conditions based on the selective transitions of nitrogen-vacancy- ($\mathrm{N}$-V) center spins in diamond. First, the relationship between the evolutions of the $\mathrm{N}$-V-center spin states and the phase difference of the MW magnetic fields, which are resonant and able to drive the transitions of the $\mathrm{N}$-V-center spins between ground-state energy levels, is deduced. Then, using a double-microstrip-line MW antenna, the variations in the Rabi frequency and maximum contrast as a function of the phase difference are experimentally revealed. Finally, the measurement of the phase difference is validated, and the sensitivity of the proof-of-principle method is estimated to be ${0.0915}^{\ensuremath{\circ}}/\sqrt{\text{Hz}}$. This method paves the way for the comprehensive quantum sensing of MW fields and has potential applications in the communication and quantum information fields.

Simultaneous realization of tunable luminescence and enhanced thermal stability in Eu2+-based blue-green phosphors for multifunctional applications

Developing a new Eu2+-doped blue-green phosphor with tunable spectral in silicate materials is challenging for a high-quality phosphor-converted white light-emitting diode. The cation substitution strategy is a valid way to concurrently modify spectral characteristics and optimize luminescence performances. Herein, a series of NaBaScxLu1-xSi2O7: Eu2+ phosphors with blue-green color-tunable luminescence have been designed. By modulating the ratio of Sc/Lu, controllable regulation of the photoluminescence and thermal stability properties can be realized simultaneously. Moreover, the initial emission intensity is monotonically increased by 2.92 times and the quantum efficiency is enhanced dramatically by introducing Sc3+. Especially, the thermal stability is boosted from 53.4% to 90.9% and the emission shifted from 485 to 504 nm is improved due to the chemical substitution of Sc in the Lu site with the lattice shrinks resulting in the Eu5d energy level farther away from the conduction band and a minimum 5d energy level closer to the ground state energy level. Furthermore, the fabricated w-LEDs with NaBaScxLu1-xSi2O7: Eu2+ blue-green phosphors and (Sr, Ba)3SiO5: Eu2+ red phosphor exhibit a high color rendering index (Ra = 87.2) and desired color-dependent temperature (CCT = 3711 K). Except for the application in solid-state illumination, the potential application of synthetic phosphors in optical anti-counterfeiting is also explored. The luminescence tunable strategy via cation substitutions simultaneously modifies emission and improves thermal stability, providing a distinctive design philosophy for the development of Eu2+-doped silicate phosphors.

Harmonic oscillator problem in the background of a topologically charged Ellis-Bronnikov–type wormhole(a)

In this paper, we study the quantum dynamics of non-relativistic particles in the background of a topological chagred Ellis-Bronnikov–type wormhole space-time. We derived the radial wave equation and obtain the eigenvalue solution through the confluent Heun equation. Afterwards, we study the harmonic oscillator problem in the same wormhole background and solve the wave equation using the same technique. In both cases, the ground state energy level E 1,l and the wave function are presented. Finally, we analyze the results and show that the eigenvalue solutions are influenced by the topological defect parameter α and the wormhole throat radius and get them modified.

Intense terahertz laser field induced electro-magneto-donor impurity associated photoionization cross-section in Gaussian quantum wires

Using expressions derived within the compact density matrix approach, the peaks of optical absorption and the changes of refractive index of a hydrogenic impurity in a GaAs/GaAlAs Gaussian quantum well wire are calculated taking into account the influence of static electric, magnetic and intense laser fields. The photoionization cross section, with normalized photon energy, is computed for different values of static electric field, magnetic field, and laser dressing parameter. The dipole moment matrix elements and the transition energy between ground and first excited state energy levels are computed as functions of quantum wire width and confinement potential depth, with and without external perturbations. Donor impurity binding energy is investigated in presence of the aforementioned electromagnetic probes, using parabolic band and effective mass approximations. The results show that the absorption coefficients depend on the transition energy difference between initial and final states involved as well as on the corresponding polarization response via dipole matrix elements. Discussed optical properties are field-sensitive and they can be tuned within the desired energy ranges using these external perturbations. • Peaks of optical absorption and changes of refractive index of a hydrogenic impurity in a GaAs/GaAlAs Gaussian quantum well wire are calculated. • They have been computed taking into account the influence of static electric, magnetic and intense laser fields. • Photoionization cross section, with normalized photon energy, is computed. • Donor impurity binding energy is investigated in the presence of aforementioned electromagnetic-probes, using parabolic band and effective mass approximations. • Discussed optical properties are field-sensitive and they can be tuned within the desired energy ranges using these external perturbations.

Simulation of the dispersed fluorescence spectrum of the NO[formula omitted][formula omitted] origin vibronic band

A vibronic Hamiltonian and transition dipole operator parametrized by high-level equation-of-motion coupled-cluster calculations are used as a basis for predicting the dispersed fluorescence spectrum of the B̃−X̃ origin band in the nitrate radical (NO3). The position and intensities of transitions to ground state vibrational levels observed in the photodetachment spectrum of the NO3 anion have previously been predicted to high fidelity with this Hamiltonian; it is expected that it also offers a basis for accurate prediction of the dispersed fluorescence spectrum. Comparison to experimental spectra provides considerable insight into various assignments. Significantly, this work joins a growing body of research that supports reassignment of the ground state ν3 vibrational fundamental to the region between 1050–1060 cm−1, which is more than 400 cm−1 below the feature to which it has traditionally been assigned. The in-plane vibrational levels below 2000 cm−1 are reviewed, with theory and experiment agreeing to within 25 cm−1 for all that have been observed experimentally. Finally, the various vibronic coupling mechanisms that affect the ground state energy levels of NO3 are summarized, and a discussion is provided about how the Lanczos algorithm can be used to efficiently calculate the dispersed fluorescence spectrum of the B̃−X̃ origin band.

Investigations on the effect of NH4Cl flux on the structural and optical properties of CdSiO3:Eu3+ nanophosphor

ABSTRACT In this work, NH4Cl flux-assisted solution combustion synthesis of Eu3+-doped CdSiO3 phosphor has been reported. The prepared phosphor has been characterised using XRD, SEM, FTIR, UV–Vis and PL techniques. The influence of NH4Cl flux on the structural, morphological and photoluminescence (PL) properties has been thoroughly investigated. The PL spectra of 5 mol% Eu3+-doped CdSiO3 nanophosphor monitored at Eu3+ emission wavelength of 613 nm, consists of four broad excitation peaks centred at 362 nm, 381 nm, 393 nm and 414 nm ascribed to Eu3+ ion transitions from its 7F0 ground state energy level to different excited energy states 5H3, 5L7, 5L6 and 5D3, respectively. CdSiO3:Eu3+ samples prepared by using 6 wt% flux showed appreciable improvement in emission intensity in the studied concentration limit. The observed improvement in the orange-red photoluminescence is due to effective substitution of Eu3+ ions in the CdSiO3 lattice.

Asymptotic profile of ground states for the Schrödinger–Poisson–Slater equation

We study the Schrödinger–Poisson–Slater equation −Δu+u+λ(I2∗|u|2)u=|u|p−2uin R3,where p∈(3,6) and λ>0. By using direct variational analysis based on the comparison of the ground state energy levels, we obtain a characterization of the limit profile of the positive ground states for λ→∞.

QFT entanglement entropy, 2D fermion and gauge fields

Entanglement and the Rényi entropies for Dirac fermions on 2 dimensional torus in the presence of chemical potential, current source, and topological Wilson loop are unified in a single framework by exhausting all the ingredients of the electromagnetic vertex operators of Zn orbifold conformal field theory. We employ different normalizations for different topological sectors to organize various topological phase transitions in the context of entanglement entropy. Pictorial representations for the topological transitions are given for the n=2 Rényi entropy.Our analytic computations reveal numerous novelties and provide resolutions for existing issues. We have settled to provide non-singular entanglement entropies that are also continuous across the topological sectors. Surprisingly, in infinite space, these entropies become exact and depend only on the Wilson loop. On a circle, we resolve to find the entropies subtly depend on the chemical potential at zero temperature, which is useful for probing the ground state energy levels of quantum systems.

A novel indolehydrazone appended salicyaldehyde platform for detection of multianalytes (Al3+, Zn2+ and F- ions): Live cell imaging

A new probe 4-bromo-2-((E)-((Z)-((5-bromo-1H-indol-2-yl) methylene) hydrazono) methyl) phenol (BHPL) has been developed and successfully employed for the detection of Al3+/Zn2+/F-ions in DMSO: H2O (9:1) system. The photophysical evaluation of BHPL with cations/anions were rationalized by UV–visible and fluorescence spectroscopy. The stoichiometric binding mode of BHPL with Al3+/Zn2+/F- ions were confirmed by Job’s plot analysis and strongly supported by1H NMR titration,19F NMR analysis and electrospray ionization mass spectroscopy (ESI-MS) techniques. The optimized geometries of BHPL with their complexes and ground state energy levels were gauged via DFT calculations. In the biological environment, BHPL could perform as an obvious fluorescent chemical tool to detect Zn2+ionsin HeLa cells and fluorescence imaging analysis in Zebrafish embryos.

Modulating the electron transfer and resistivity of Ag plasma implanted and assisted MoS2 nanosheets

A simple and controllable technique has been proposed for single-step co-sputtering of homogeneous Ag-power/MoS2 film as excellent photoelectric materials. Interestingly, the binding mode of Ag plasma implanted and assisted MoS2 nanosheets are investigated by adjusting the sputtering power. The diffraction peaks of Ag2S/Ag and valence electronic structure of Ag0/Ag1+ have been studied by a combined analysis of X-ray diffraction and X-ray photoelectron spectroscopy measurements, which confirm the implantation of Ag on MoS2 nanosheets. More specifically, the slight shift of the Mo3d/S2p demonstrated that the electrons moved from the MoS2 band gap to the ground state energy level of the Ag NPs. The significantly excellent linear absorption characteristic has been demonstrated, which can be attribute to the synergetic effects of SPR and the lower energy barrier of internal defects in the more homogeneous film. The implantation and assistance of Ag plasmon not only increased the visible/near-infrared absorption and emission of MoS2 nanosheets, but also induced the high amplification of the local electric field intensity in MoS2 nanosheets. Our work provides an effective strategy for the preparation of plasmonic Ag implanted and assisted Few-Layers MoS2 nanosheets and prompts their wider applications in visible/near-infrared devices.

Remarks on the Dirac Kepler/Coulomb problem with a space-dependent mass term

We investigate the Dirac Kepler/Coulomb (KC) problem in -dimensions where the charged particle (an electron) is simultaneously affected by a position-dependent effective mass term. In polar coordinates, we examine two instances: (i) the quantum dynamics of an electron moving in the presence of both a Coulomb potential and a Coulomb-like scalar potential. This problem turns to be exactly solvable; (ii) the planar dynamics of a self-interacting electron in a Coulomb potential where nonlinearities are introduced via a scalar self-interaction, known as the Soler model. We obtain the approximate (nonlinear) ground-state energy levels together with their respective eigenfunctions. Thus, within the same framework, we present two different relativistic quantum-mechanical models which can be further explored.

Two-body bound states through Yukawa forces and perspectives on hydrogen and deuterium

We present and discuss numerical solutions to a two-body quantum bound state problem closely related to that of the hydrogen atom and the deuterium nucleus. The forces binding the particles of our system are Yukawa forces, which fall off with distance faster than the Coulomb force and arise for non-relativistic particles whose interactions are mediated by massive scalar or vector particles; the Coulomb force arises in the limit of massless mediators such as photons. We use the solutions to explain several features of deuterium. We also present heuristic estimates of ground state energies and energy level degeneracy breaking. Studying this Yukawa two-body system provides insights into hydrogen, deuterium, and two-body bound states, generally. We describe our undergraduate-accessible procedure for numerically solving non-relativistic two-body bound state problems with mathematica in the appendix.

A dual responsive probe based on bromo substituted salicylhydrazone moiety for the colorimetric detection of Cd2+ ions and fluorometric detection of F‒ ions: Applications in live cell imaging

A dual responsive probe based on bromo substituted salicylhydrazone moiety for the colorimetric detection of Cd2+ ions and fluorometric detection of F‒ ions: Applications in live cell imaging