State Energy Research Articles

Magnetotransport and activation energy of the surface states in Cd3As2 thin films

Magnetotransport and activation energy of the surface states in Cd3As2 thin films

Spectrum of two-flavored spin-zero heavy dibaryons in lattice QCD

We present the ground state energy spectra of two-flavored heavy dibaryons in the spin-singlet channel. In particular, the ground state masses of ΩllQΩllQ,ΩQlQΩllQ, and ΩQlQΩQlQ states are computed and compared with their respective lowest noninteracting energy levels, where the flavor Q∈(c,b) denotes charm and bottom quarks, and the other flavor l∈s,c,b represents strange, charm and bottom, respectively. Considering their valence quark structures, these hadrons could be thought of as the heavy flavor analogs of spin-singlet nucleon-nucleon states. The gauge configurations employed in this study are highly improved staggered quark ensembles with Nf=2+1+1 flavors, generated by the MILC collaboration, at four lattice spacings, namely a=0.1207, 0.0888, 0.0582, and 0.0448 fm. The aforementioned states are also computed at different quark masses, between ms≤ml≤mb, including at unphysical heavy quark masses, to explore the quark mass dependence of any possible binding. For the dibaryon states ΩbbcΩbbc,ΩccbΩccb, and ΩccbΩbbc, we find a clear evidence of an energy level below their respective noninteracting energy levels. In addition, for these dibaryons at quark masses mc<ml≤mb, a trend is found where the gap, between the lowest energy levels and the respective lowest noninteracting levels, increases as the quark mass ml increases. We also study the heavy quark spin-symmetry and its breaking for these heavy dibaryons. Published by the American Physical Society 2025

Niobium-buffered tantalum for a superconducting fluxonium qubit

Abstract We use a magnetron sputtering system to grow a tantalum film on a sapphire substrate with a niobium buffer layer at room temperature. The tantalum film is in $\alpha$-phase, which is preferred for superconducting quantum devices. We fabricate a superconducting heavy fluxonium qubit with this niobium-buffered tantalum film, which demonstrates good performance. Forbidden transitions and sideband transition phenomena between specific energy levels are observed. Due to the specific design parameters, the fluxonium described herein exhibits high anharmonicity while maintaining a long decoherence time in the higher energy states, making it well-suited for use as a qudit and enabling high-dimensional quantum computation. With further optimization of the film deposition process, superconducting qubits other than fluxoniums with higher performance are expected to be obtained using these multilayer films grown at room temperature.

Assessing the Moist and Dry Static Energies in the Atmosphere as a Van Der Waals Gas in 2015 and 2017 over the Metropolitan Region of Natal-RN, Brazil

This study evaluated the monthly average of the enthalpy, geopotential, latent heat content, moist static energy, and dry static energy at several levels of the atmosphere as a Van Der Waals gas from radiosonde data at 00:00 UTC and 12:00 UTC over the metropolitan region of Natal-RN-Brazil. The years 2015 and 2017 were considered because they presented more than 70% of complete data, with days coinciding at both times. To construct the vertical profiles of the variables, the density, specific humidity, and geopotential were calculated at each level through a mathematical approximation based on the Calculus. The Van der Waals-like atmosphere results showed that the latent heat content compensated for any change in enthalpy and potential energy from the surface to the mid-troposphere. Energy was exchanged among enthalpy, geopotential, and latent heat content, showing a roughly constant moist static energy. The moist static energy was a conserved quantity under adiabatic and hydrostatic transformations, although the dry static energy was not conserved. The results of the atmosphere as a Van Der Waals gas and the atmosphere as an ideal gas were compared, proving to be similar.

Closed-channel parameters of Feshbach resonances

This work investigates how the closed channel of a Feshbach resonance is characterised by experimental observables. Surprisingly, it is found that the two-body observables associated with the Feshbach resonance can be insensitive to the properties of the closed channel. In particular, it is impossible in this situation to determine the energy of the bound state causing the resonance from the usual experimental data. This is the case for all magnetic Feshbach resonances in ultracold atoms, due to their deep two-body interaction potentials. This insensitivity highlights a major difference with Feshbach resonances that involve shallow interaction potentials, such as hadron resonances. It appears however that short-range two-body correlations and three-body observables are affected by a parameter of the closed channel called the “closed-channel scattering length”. A photoassociation experiment is proposed to measure this parameter in ultracold atom systems.

Study on the Influence of External Electric Field Control and Vibrational Quantum Effect on the Charge Separation Mechanism in Fullerene-Based Systems.

Based on the DCV-C60 system of fullerene acceptor organic solar cell active materials, the charge transfer process of D-A type molecular materials under the action of an external electric field (Fext) was explored. Within the range of electric field application, the excited state characteristics exhibit certain regular changes. Based on reducing the excitation energy, the excitation mode shows a trend of developing toward low excited states. The effect of solvent polarity on the stability and reorganization energy of the charge transfer state was investigated. The dependence of charge separation parameters on specific molecular structures within the electric field range was studied, proving that the electric field set along the electron transfer direction can indeed accelerate charge separation. The influence of vibrational modes on the charge separation process was studied, and the results showed that the vibrational quantum tunneling effect significantly promoted the charge separation. Therefore, considering the vibrational excitation effect and the perturbation of the nuclear-electron interaction is crucial for more accurate simulation of the electron-vibration coupling process in the excited state.

Photochromic properties calculation of diaryl maleic anhydride

Abstract In the calculation of the photochromic mechanism of (2,3-di(3-furyl)maleic anhydride, DFMA) ( as reported in Acta Phys. Sinica. 2021, 70(16): 163101), it was discovered that between the open-ring and closed-ring stable configurations, the potential energy curves of the electronic ground state (S0) and the first excited state (S1) exhibited an ‘X’ shape distribution along the reaction path. The conversion between open-ring and closed-ring occurs at the intersection of the potential energy curves, and a photoinduced ring-closing reaction accompanied by fluorescence was predicted, while a photoinduced ring-opening reaction was not. In this work, we apply the same method to investigate the mechanism of the photoinduced molecular switching process in the compounds of 2,3-di(3-thienyl)maleic anhydride(DTMA) and 2,3-di(3-pyrrolyl)maleic anhydride(DPMA). The transition state (TS) and minimum energy path (MEP) between the open-ring and closed-ring were determined by using the nudged elastic band (NEB) method. The potential energy curves of the lowest eight single excited states of DxMA(x = F, T, P) were computed based on the molecular configurations corresponding to the MEP curve (ground state S0). Interestingly, only the first excited state (S1 state) has a minimum value in the TS configuration among all eight excited states. That is, between the open-ring and closed-ring, the potential curves of S0 and S1 display an ‘X’ shape with a cross occurred at the TS configuration. The calculation of the S1←S0 resonance vibronic absorption spectrum of the open-ring/closed-ring state via molecular dynamics reveals that the transition intensity of the closed-ring state is 3 ∼ 5 times that of the open-ring state, which demonstrates that the efficiency of the closed-ring to the open-ring is higher.

Aromatic ring compounds with different conjugation degrees in a boronic acid matrix to realize multicolor phosphorescence for time division colorful multiplexing.

Long lifetime multicolor phosphorescence materials possess excellent optical properties and have important application prospects in the fields of advanced anti-counterfeiting and information encryption. However, realizing long lifetime and color-tunable room temperature phosphorescent (RTP) carbon dot (CD) materials has proved challenging. In this study, the organic precursor molecules 2-phenethylamine (2-Ph), 9-aminophenanthrene (9-Ph) and 1-aminopyrene (1-Py) with different degrees of conjugation were selected to synthesize RTP CD composites: 2-Ph@BA, 9-Ph@BA and 1-Py@BA were synthesized by mixing with a boric acid (BA) matrix under high temperature pyrolysis. During high temperature pyrolysis, CDs form effective covalent and hydrogen bonds with the BA matrix to promote RTP activity and obtain a stable triplet state, which suppresses nonradiative transitions and leads to long lifetime RTP. Besides, as the conjugation of the organic precursor molecules 2-Ph, 9-Ph and 1-Py gradually increases, it results in a gradual decrease of the triplet state energy T1. Thus, 2-Ph@BA, 9-Ph@BA and 1-Py@BA RTP emission showed a significant redshift, leading to green, yellow and red phosphorescence colors, respectively. Finally, RTP CD composites are used in information security and time division colorful multiplexing based on the synthesized samples with different phosphorescence colors and lifetimes.

Dark coloured scalars impact on single and di-Higgs production at the LHC

The search for Dark Matter (DM) at colliders is primarily pursued via the detection of missing energy in particular final states. These searches are based on the production and decay processes where final states include DM particles and at least one Standard Model (SM) particle. DM will then reveal itself as missing energy. An alternative form to get a hint of a dark sector is via loop contribution to SM processes. In this case, it is not even relevant if the new particles have their origin in the dark sector of the model. In this work we discuss the impact of an arbitrary number of coloured scalars with Z2-odd parity in single Higgs and double Higgs production at the Large Hadron Collider (LHC), and we show their complementarity. We determine the range of variation of the corrections relative to the SM for an arbitrary number of coloured scalars n. We discuss the cases n=1 and n=2 for a specific model in more detail, which includes direct searches at the LHC. We also find that the electroweak observable T parameter imposes significant restrictions on the difference of the heavy coloured scalar masses.

Orbital angular momentum light interacted with double quantum dot-metal nanoparticle hybrid structure under spontaneous coherence

This work studies the generation of the orbital angular momentum (OAM) beam in the double quantum dot-metal nanoparticle (DQD-MNP) system under the application of the OAM beam. First, an analytical model is derived to attain the relations of probe and generated fields as a distance function in the DQD-MNP system under OAM applied field and spontaneously generated coherence (SGC) components. The calculation here is of material property; it differs from others by calculating energy states of the DQDs and the computation of the transition momenta between quantum dot (QD)-QD and QD-wetting layer (WL) transitions. The orthogonalized plane wave (OPW) calculates QD-WL transitions and their momenta. The momentum calculation is essential to specify the Rabi frequency of the input field. Such characteristics are not used in earlier models. The results show that SGC is vital in increasing the generated field. The signal field generated in the DQD-MNP system doubles that from the DQD system alone. So, the DQD-MNP system is preferred to the DQD system. The generated field in the DQD-MNP for the strong coupling DQD-MNP system is higher than that for the weak coupling. Increasing the distance separating the DQD-MNP reduces the generated field. Higher OAM number reduce the generated field at a long distance in the device. The model is then extended to study the effect of incoherent pumping () and the relations are modified to cover this part. The results show that reduces the generated field. While the results that compare the weak and strong coupling appear for the first, others compare well to the literature.

Non-compact extra dimensions and flavor dependence of cc̄ and bb̄ mesons masses in a hot QCD medium with lattice, LO and NLO parametrizations of the Debye mass

In this paper, we consider a heavy quarkonium state in a hot QCD medium, namely the ground state of charmonium and bottomonium. The quark–antiquark potential is proposed in the form of a temperature-dependent Cornell potential, and is extended to include a temperature-dependent parameter. Then, for the proposed potential with different parametrizations of the Debye mass, the N-dimensional Schrödinger equation is analytically solved using the biconfluent Heun equation. The obtained energy eigenvalues and wave functions are employed to study the flavor dependence, the effect of dimensionality and the influence of the additional term on the mass and binding energy of 1S state of charmonium and bottomonium at finite temperature. The findings of this research are compared to those from past studies. We concluded that this work provides a simple and consistent description of quarkonium states at finite temperature in a hot QCD medium, highlighting the effect of noncompact extra dimensions and the flavor dependence of the binding energies of heavy quarkonia.

DNA Triplet Energies by Free Energy Perturbation Theory.

Determining the energetics of triplet electronic states of nucleobases in the biological macromolecular environment of nucleic acids is essential for an accurate description of the mechanism of photosensitization and the design of drugs for cancer treatment. In this work, we aim at developing a methodological approach to obtain accurate free energies of triplets in DNA beyond the state of the art, able to reproduce the decrease of triplet energies measured experimentally for T in DNA (270 kJ/mol) vs in the isolated nucleotide in aqueous solution (310 kJ/mol). For such purposes, we adapt the free energy perturbation method to compute the free energy related to the transformation of a pure singlet state into a pure triplet state via "alchemical" intermediates with mixed singlet-triplet nature. By this means, standard deviation errors are only a few kJ/mol, contrary to the large errors of tenths of kJ/mol obtained by averaging the singlet and triplet energies derived from molecular dynamics simulations. The reduced statistical errors obtained by the free energy perturbation approach allow us to rationalize with confidence the triplet stabilization observed experimentally when comparing the thymine nucleotide and thymine in DNA. Spin polarization rather than excimer interactions between the π-stacked nucleobases originates the lower values of the triplet energies in DNA. The developed approach implemented in QM3 shall be useful for determining free energies of triplets and other states like ionic or charge separation states in any other macromolecular system with impact in biomedicine and materials science.

Circularity in polydiketoenamine thermoplastics via control over reactive chain conformation.

Controlling the reactivity of bonds along polymer chains enables both functionalization and deconstruction with relevance to chemical recycling and circularity. Because the substrate is a macromolecule, however, understanding the effects of chain conformation on the reactivity of polymer bonds emerges as important yet underexplored. Here, we show how oxy-functionalization of chemically recyclable condensation polymers affects acidolysis to monomers through control over distortion and interaction energies in the rate-limiting transition states. Oxy-functionalization of polydiketoenamines at specific sites on either the amine or triketone monomer segments increased acidolysis rates by more than three orders of magnitude, opening the door to efficient deconstruction of linear chain architectures. These insights substantially broaden the scope of applications for polydiketoenamines in a circular manufacturing economy, including chemically recyclable adhesives for a diverse range of surfaces.

Many-body density of states of bosonic and fermionic gases: a combinatorial approach

Abstract We use a combinatorial approach to obtain exact expressions for the many-body density of states of fermionic and bosonic gases with equally spaced single-particle spectra. We identify a mapping that reveals a remarkable property, namely, fermionic and bosonic gases have the same many-body density of states, up to a shift corresponding to ground state energy. Additionally, we show that there is a regime, comprising the validity range of the Bethe approximation, where the many-body density of states becomes independent of the number of particles.

Impact of Subsurface Oxygen on CO2 Charging Energy Changes in Cu Surfaces.

Subsurface oxygen in oxide-derived copper catalysts significantly influences CO2 activation. However, its effect on the molecular charging process, the key to forming the CO2δ- intermediate, remains poorly understood. We employ many-body perturbation theory to investigate the impact of the structural factors induced by the subsurface oxygen on the charged activation of CO2. By computing the molecular single-particle state energy of the electron-accepting orbital on the Cu (111) surface, we examined how this molecular quasi-particle (QP) energy changes with the varying vicinity of adsorption and multiple-subsurface oxygen configuration. We demonstrate that subsurface oxygen impairs CO2 charging, with its presence and coverage being influential factors. However, we remark that density functional theory calculations do not predict such an excitation energy discrepancy induced by subsurface oxygen. The nonlocal potential proves to be substantial for accurate excitation energy predictions yet is not sensitive to minor atomic structural changes. More importantly, state delocalization and hybridization are critical for determining QP energy. These insights are enlightening for designing atomic architectures to optimize catalytic performance on modified surfaces.

Bifunctional Group Modulation Strategy Enables MR-TADF Electroluminescence Toward BT.2020 Green Light Standard.

Herein, a parallel "bifunctional group" modulation method is proposed to achieve controlled modulation of the emission wavelength and full-width at half-maximum (FWHM) values. As a result, three proof-of-concept emitters, namely DBNDS-TPh, DBNDS-DFPh, and DBNDS-CNPh, are designed and synthesized, with the first functional dibenzo[b,d]thiophene unit concurrently reducing the bandgap and elevate their triplet state energy. A second functional group 1,1':3',1″-triphenyl, and electron acceptors 1,3-difluorobenzene and benzonitrile, respectively, to deepen the HOMO and LUMO levels. Accordingly, the CIE coordinates of DBNDS-TPh, DBNDS-DFPh, and DBNDS-CNPh are (0.13, 0.77), (0.14, 0.77), and (0.14, 0.76) respectively, in a dilute toluene solution. This marks the first instance of achieving a CIEy value of 0.77 in dilute toluene solutions. Significantly, the non-sensitized pure-green OLEDs based on DBNDS-TPh and DBNDS-DFPh demonstrate peak EQE of 35.0% and 34.5%, with corresponding CIE coordinates of (0.18, 0.75), (0.17, 0.76) at the doping concentration of 1 wt.%, representing the first green OLED with a CIEy value reaching 0.76 in a bottom-emitting device structure as reported in the literature.

Thermal Decomposition of Calcium Carbonate at Multiple Heating Rates in Different Atmospheres Using the Techniques of TG, DTG, and DSC

To grasp the decomposition reaction rule of calcium carbonate in cement raw material, the thermogravimetric analyzer (TG), derivative thermogravimetric (DTG), and differential scanning calorimeter (DSC) were used for analysis. Calcium carbonate samples were heated linearly at multiple heating rates of 10, 20, 30, and 40 °C/min in the atmospheres of N2 and 70% N2 + 30% O2, respectively. The decomposition kinetics was investigated using a double extrapolation method. Kinetic parameters of the thermal decomposition and the most probable mechanism function were determined in two different atmospheres. The results show that TG, DTG, and DSC curves moved to a higher temperature with the increase in heating rate, and the addition of O2 in the reaction atmosphere had almost no effect on the change in the decomposition curve. Additionally, the activation energy of the initial state in the formation of the new nucleus obtained using the double extrapolation method was 232.13 kJ/mol in the N2 atmosphere, and the most probabilistic mechanistic function was G(α) = 1 − (1 − α)1/2. The chemical reaction process was consistent with the contracted cylinder mechanism model of phase boundary reaction. Moreover, the activation energy of the initial state in the formation of the new nucleus was 233.79 kJ/mol in the 70% N2 + 20% O2 atmosphere, and the chemical reaction process was consistent with that of the N2 atmosphere. Therefore, these results could determine the decomposition temperature and decomposition rate of calcium carbonate. This was important for understanding the thermal stability and processing temperature range of polymer materials, especially the application and potential in production and scientific research.

The divide expand consolidate scheme for unrestricted second order Møller-Plesset perturbation theory ground state energies.

The linear scaling divide-expand-consolidate (DEC) framework is expanded to include unrestricted Hartree-Fock references. By partitioning the orbital space and employing local molecular orbitals, the full molecular calculation can be performed as independent calculations on individual fragments, making the method well-suited for massively parallel implementations. This approach also incorporates error control through the fragment optimization threshold (FOT), which maintains precision and consistency throughout the calculations. A benchmark was conducted for correlation energies of open-shell systems and the relative energies of both open- and closed-shell molecules at the MP2 level of theory. The full calculation result is achieved as the FOT approaches zero. For correlation energies, an FOT of 10-3 is sufficient to recover over 98% of the full result in all cases. However, for relative energies and the electronic energy component of oxidation potentials, a tighter FOT of 10-4 is required to keep the DEC error within 10% for both open- and closed-shell molecules. This is likely due to a lack of systematic error cancellation for the molecules with vastly different chemical natures. Therefore, for accurate relative energies, the FOT should be an order of magnitude lower, and additional caution is needed, particularly for large systems. The DEC method extension to unrestricted references maintains favorable features of linear scaling and can be implemented in a massively parallel algorithm to calculate correlation energies for large open-shell systems.

Surface Interactive Assembly of Ruthenium Based Janus Bimetallic Nanoparticles With Active Dual‐Function Sites for Efficient Use in CO2 Utilization

AbstractNoble bimetallic nanoparticles (NPs) are nowadays essential in various applications, like CO2 utilization by dry reforming of methane (DRM), due to their unique and potential properties. A synthesis method for Ru based Janus‐structured NPs is presented via surface interactive assembly of deposited Ru and emerged Ni species from carefully tailored perovskite oxide support. As noble‐metals typically result in the alloy, an exclusive formation mechanism is introduced by utilizing Ru energetically favorable for the Janus phase by lower ground state energy from interactions between the strongly embedded cluster and perovskite surface. Consequently, noticeable Janus NPs, controllable in size and composition with active configuration by dual‐function sites and interface strains, are well‐produced with high distribution. DRM performance highly exceeds conventional Ru over 5 times in TOFs for both CO2 and CH4 with improved stability maintaining H2/CO for 100 h without sintering at harsh reaction conditions, which comprehensively exhibits distinct advantages over recent works. Fundamental studies indicate combined electronic d‐band structures proving distinctive CO2 dissociation and CH4 activation, involving efficient dehydrogenation and CO production via surface oxygenation, considerably suppresses coking. This approach presents a potential avenue to surmount constraints on designing bimetallic NPs in any structured oxide systems for effective materials in various low carbon relevant industries.

The impact of effective mass mismatch and quantum dot size on the interband absorption and sub-bandgap photocurrent of box-shaped InAs/GaAs quantum dot-intermediate band solar cells

The InAs/GaAs quantum dot intermediate band solar cells (QD-IBSCs) have the potential for high conversion efficiency. In practice, their efficiencies have not reached 20%. In this study, the confined energy levels, interband absorption coefficients, and absorbed sub-bandgap photocurrent densities are calculated with QD size using equal effective mass and effective mass mismatch for the box-shaped InAs/GaAs QD system. The four-band k·p model was applied to the InAs/GaAs QD system. The energy of IB levels with the effective mass mismatch decreased compared with the equal effective mass. The interband photocurrent density increased with effective mass mismatch since more confined energy states contributed to interband absorption. If the in-plane QD density raised from 4×1010cm-2 to 4×1011cm-2, the interband photocurrent density increased from 0.58 to 5.19 mA/cm2 for equal effective mass and 0.99 to 8.38 mA/cm2 for the effective mass mismatch with 16 nm × 16 nm × 6 nm of QD size, under one sun concentration. Increasing the QD size also allows additional IB states within the forbidden band; thus, the interband photocurrent increases with QD size. The interband photocurrent density for 10 nm and 16 nm QD widths is 0.39 mA/cm2 and 0.99 mA/cm2, respectively.