ﻻ يوجد ملخص باللغة العربية
We propose that spatial density matrices, which are singularly important in the study of quantum entanglement, encode the electronic fluctuations and correlations responsible for covalent bonding. From these density matrices, we develop tools that allow us to analyse how many body wave functions can be broken up into real space pieces. We apply these tools to the first row dimers, and in particular, we address the conflicting evidence in the literature about the presence of an inverted fourth bond and anti-ferromagnetic correlations in the $text{C}_2$ molecule. Our results show that many body effects enhance anti-ferromagnetic fluctuations but are not related to the formation of an inverted fourth bond. We identify two inverted bonds in the $text{C}_2$ molecule and establish their correspondence to the bonds in the $text{Be}_2$ molecule. Additionally, we provide a new interpretation of the Mayer index, introduce partial bonds to fix deficiencies in molecular orbital theory, and prove the Hartree-Fock wave function for C$_{2}$ is not a triple bond. Our results suggest that entanglement-based methods can lead to a more realistic treatment of molecular and extended systems than possible before.
The covalent-like characteristics of hydrogen bonds offer a new perspective on intermolecular interactions. Here, using density functional theory and post-Hartree-Fock methods, we reveal that there are two bonding molecular orbitals (MOs) crossing th
We introduce for SU(2) quantum spin systems the Valence Bond Entanglement Entropy as a counting of valence bond spin singlets shared by two subsystems. For a large class of antiferromagnetic systems, it can be calculated in all dimensions with Quantu
Several algorithms have been proposed to calculate the spatial entanglement spectrum from high order Renyi entropies. In this work we present an alternative approach for computing the entanglement spectrum with quantum Monte Carlo for both continuum
We study the quench dynamics of entanglement spectra in the Kitaev chain with variable-range pairing quantified by power-law decay rate $alpha$. Considering the post-quench Hamiltonians with flat bands, we demonstrate that the presence of entanglemen
We investigate the entanglement spectra arising from sharp real-space partitions of the system for quantum Hall states. These partitions differ from the previously utilized orbital and particle partitions and reveal complementary aspects of the physi