53 citations · 297 across the 28 of their papers we have counts for
28 papers
Surface coupling of NV centers over nanoscale lengths
Arsineh Apelian, Mariya Romanova, Vojtech Vlcek
Shallow nitrogen-vacancy (NV-) centers in diamond are among the most promising quantum sensors, offering high sensitivity and nanoscale spatial resolution. These systems are, howev…
Renormalization of States and Quasiparticles in Many-body Downfolding
Annabelle Canestraight, Zhen Huang, Vojtech Vlcek
We explore the principles of many-body Hamiltonian complexity reduction via downfolding on an effective low-dimensional representation. We present a unique measure of fidelity betw…
Impact of Subsurface Oxygen on CO2 Charging Energy Changes in Cu Surfaces
Xiaohe Lei, Vojtech Vlcek
Subsurface oxygen in oxide-derived copper catalysts significantly influences CO activation. However, its effect on the molecular charging process, the key to forming the CO$_2^…
Delocalization of Quasiparticle Moiré States in Twisted Bilayer hBN
Arsineh Apelian, Annabelle Canestraight, Songyuan Liu +1
Twisted bilayers host many emergent phenomena in which the electronic excitations (quasiparticles - QPs) are closely intertwined with the local stacking order. By inspecting twiste…
Fidelity and variability in the interlayer electronic structure of the kagome superconductor CsV3Sb5
Aurland K. Watkins, Dirk Johrendt, Vojtech Vlcek +2
The AV3Sb5 (A = K, Rb, Cs) kagome materials host an interplay of emergent phenomena including superconductivity, charge density wave states, and non-trivial electronic structure to…
Efficient Quasiparticle Determination beyond the Diagonal Approximation via Random Compression
Annabelle Canestraight, Xiaohe Lei, Khaled Ibrahim +1
Calculations of excited states in Green's function formalism often invoke the diagonal approximation, in which the quasiparticle states are taken from a mean-field calculation. Her…
Exceptional spatial variation of charge injection energies on plasmonic surfaces
Xiaohe Lei, Annabelle Canestraight, Vojtech Vlcek
Charge injection into a molecule on a metallic interface is a key step in many photo-activated reactions. The energy barrier for injection is paralleled with the lowest particle an…
On the unimportance of memory for the time non-local components of the Kadanoff-Baym equations
Cian C. Reeves, Yuanran Zhu, Chao Yang +1
The generalized Kadanoff-Baym ansatz (GKBA) is an approximation to the Kadanoff-Baym equations (KBE), that neglects certain memory effects that contribute to the Green's function a…
Spatial Decay and Limits of Quantum Solute-Solvent Interactions
Guorong Weng, Amanda Pang, Vojtech Vlcek
Molecular excitations in the liquid-phase environment are renormalized by the surrounding solvent molecules. Herein, we employ the GW approximation to investigate the solvation eff…
Disordered Hyperuniform Solid State Materials
Duyu Chen, Houlong Zhuang, Mohan Chen +3
Disordered hyperuniform (DHU) states are recently discovered exotic states of condensed matter. DHU systems are similar to liquids or glasses in that they are statistically isotrop…
Embedding vertex corrections in GW self-energy: theory, implementation, and outlook
Guorong Weng, Rushil Mallarapu, Vojtech Vlcek
The vertex function () within the Green's function formalism encapsulates information about all higher-order electron-electron interaction beyond those mediated by density fluct…
Dynamical downfolding for localized quantum states
Mariya Romanova, Guorong Weng, Arsineh Apelian +1
We introduce an approach to treat localized correlated electronic states in the otherwise weakly correlated host medium. Here, the environment is dynamically downfolded on the corr…
Dynamic Mode Decomposition for Extrapolating Non-equilibrium Green's Functions Dynamics
Cian C. Reeves, Jia Yin, Yuanran Zhu +3
The HF-GKBA offers an approximate numerical procedure for propagating the two-time non-equilibrium Green's function(NEGF). Here we compare the HF-GKBA to exact results for a variet…
Stochastic many-body calculations of moiré states in twisted bilayer graphene at high pressures
Mariya Romanova, Vojtech Vlcek
Atomistic first principles many-body computational studies were so far limited by the system size. In this work, we apply and expand the stochastic GW method allowing calculations…
Efficient treatment of molecular excitations in the liquid phase environment via stochastic many-body theory
Guorong Weng, Vojtech Vlcek
Accurate predictions of charge excitation energies of molecules in the disordered condensed phase are central to the chemical reactivity, stability, and optoelectronic properties o…
Tuning the range separation parameter in periodic systems
Wenfei Li, Vojtech Vlcek, Helen Eisenberg +3
Kohn-Sham DFT with optimally tuned range-separated hybrid (RSH) functionals provides accurate and nonempirical fundamental gaps for a wide variety of finite-size systems. The stand…
Are multi-quasiparticle interactions important in molecular ionization?
Carlos Mejuto-Zaera, Guorong Weng, Mariya Romanova +4
Photo-emission spectroscopy directly probes individual electronic states, ranging from single excitations to high-energy satellites, which simultaneously represent multiple quasipa…
Decomposition and embedding in the stochastic self-energy
Mariya Romanova, Vojtěch Vlček
We present two new developments for computing excited state energies within the approximation. First, calculations of the Green's function and the screened Coulomb interaction…
Stochastic many-body perturbation theory for Moiré states in twisted bilayer phosphorene
Jacob Brooks, Guorong Weng, Stephanie Taylor +1
A new implementation of stochastic many-body perturbation theory for periodic 2D systems is presented. The method is used to compute quasiparticle excitations in twisted bilayer ph…
Stochastic vertex corrections: linear scaling methods for accurate quasiparticle energies
Vojtech Vlcek
New stochastic approaches for the computation of electronic excitations are developed within the many-body perturbation theory. Three approximations to the electronic self-energy a…
Stochastic Time-Dependent DFT with Optimally Tuned Range-Separated Hybrids: Application to Excitonic Effects in Large Phosphorene Sheets
Vojtech Vlcek, Roi Baer, Daniel Neuhauser
We develop a stochastic approach to time-dependent DFT with optimally-tuned range-separated hybrids containing non-local exchange, for calculating optical spectra. The attractive e…
Nonmonotonic band gap evolution in bent phosphorene nanosheets
Vojtech Vlcek, Eran Rabani, Roi Baer +1
Nonmonotonic bending-induced changes of fundamental band gaps and quasiparticle energies are observed for realistic nanoscale phosphorene nanosheets. Calculations using stochastic…
First principles absorption spectra of Au nanoparticles: from quantum to classical
Samuel Hernandez, Yantao Xia, Vojtěch Vlček +4
Absorption cross-section spectra for gold nanoparticles were calculated using fully quantum Stochastic Density Functional Theory and a classical Finite-Difference Time Domain (FDTD…
Quasiparticle spectra from molecules to bulk
Vojtech Vlcek, Eran Rabani, Daniel Neuhauser
A stochastic cumulant GW method is presented, allowing us to map the evolution of photoemission spectra, quasiparticle energies, lifetimes and emergence of collective excitations f…