Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/physrevb.44.3191 | DOI Listing |
Phys Rev Lett
December 2024
International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore 560089, India.
We consider an analytically tractable model that exhibits the main features of the Page curve characterizing the evolution of entanglement entropy during evaporation of a black hole. Our model is a gas of noninteracting fermions on a lattice that is released from a box into the vacuum. More precisely, our Hamiltonian is a tight-binding model with a defect at the junction between the filled box and the vacuum.
View Article and Find Full Text PDFSci Adv
November 2024
Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
Through first-principles calculations based on density functional theory, we investigate the crystal and electronic structures of twisted bilayer BaTiO. Our findings reveal that large stacking fault energy leads to a chiral in-plane vortex pattern that was recently observed in experiments. We also found nonzero out-of-plane local dipole moments, indicating that the strong interlayer interaction might offer a promising strategy to stabilize ferroelectric order in the two-dimensional limit.
View Article and Find Full Text PDFMaterials (Basel)
September 2024
Faculty of Technical Physics, Information Technology and Applied Mathematics, Institute of Physics, Lodz University of Technology, 93-005 Lodz, Poland.
A derivation of a tight-binding model from Schrödinger formalism for various topologies of position-based semiconductor qubits is presented in the case of static and time-dependent electric fields. The simplistic tight-binding model enables the description of single-electron devices at a large integration scale. The case of two electrostatically Wannier qubits (also known as position-based qubits) in a Schrödinger model is presented with omission of spin degrees of freedom.
View Article and Find Full Text PDFJ Phys Condens Matter
July 2024
Department of Physics, University of Rome Tor Vergata and INFN, Via della Ricerca Scientifica 1, Roma 00133, Italy.
Two approaches are presented here to analyze the absorption resonances between carbynes and cyclo[n]carbons, namely the analytical tight-binding model to calculate the optical selection rules of cumulenic atomic rings and chains and thetime-dependent density functional theory for the optical investigation of polyynic carbon ring and chains. The optical absorption spectra of the carbon ring match that of the finite chain when their eigen energies align following theNring=2Nchain+2rule, which states that the number of atoms in an atomic ringNringis twice the number of atoms on a finite chainNchainwith two additional atoms. Two representative atomic chains are chosen for our numerical calculations, specifically carbynes withN=7and8carbon atoms as optical resonance spectra match to a recently synthesized carbon ring called cyclo[18]carbon.
View Article and Find Full Text PDFJ Comput Chem
October 2024
Institute of General, Inorganic and Theoretical Chemistry Center for Chemistry and Biomedicine, University of Innsbruck, Innsbruck, Austria.
The previously introduced workflow to achieve an energetically and structurally optimized description of frontier bonds in quantum mechanical/molecular mechanics (QM/MM)-type applications was extended into the regime of computational material sciences at the example of a layered carbon model systems. Optimized QM/MM link bond parameters at HSEsol/6-311G(d,p) and self-consistent density functional tight binding (SCC-DFTB) were derived for graphitic systems, enabling detailed investigation of specific structure motifs occurring in graphene-derived structures quantum-chemical calculations. Exemplary molecular dynamics (MD) simulations in the isochoric-isothermic (NVT) ensemble were carried out to study the intercalation of lithium and the properties of the Stone-Thrower-Wales defect.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!