First-principles study of electron transport through the single-molecule magnet Mn12 (2009)
Barraza-Lopez, Salvador, Park, Kyungwha, Garcia-Suarez, Victor, Ferrer, Jaime
We examine electron transport through a single-molecule magnet Mn12 bridged between Au electrodes using the first-principles method. We find crucial features which were inaccessible in model...
Barraza-Lopez, Salvador, Park, Kyungwha, García-Suárez, Víctor, Ferrer, Jaime
Electronic transport through a single-molecule magnet Mn$_{12}$ in a two-terminal set up is calculated using the non-equilibrium Green's function method in conjunction with density-functional theory....
Transition rates for a S \ge 1 model coupled to a phonon bath (2007)
We investigate transition rates between different spin configurations for $S \ge 1$ spins weakly coupled to a $d$-dimensional phonon bath. This study is motivated by understanding observed...
First-principles study of a single-molecule magnet Mn_{12} monolayer on the Au(111) surface (2007)
Barraza-Lopez, Salvador, Avery, Michael C., Park, Kyungwha
The electronic structure of a monolayer of single-molecule magnets Mn$_{12}$ on a Au(111) surface is studied using spin-polarized density-functional theory. The Mn$_{12}$ molecules are oriented such...
Electronic structure and vibrational spectra of C2B10-based clusters and films (2006)
Park, Kyungwha, Pederson, M. R., Boyer, L. L., Mei, Wai-Ning, Sabirianov, Renat F., Zeng, Xiao Cheng, ...
The electronic structure, total energy, and vibrational properties of C2B10H12 (carborane)molecules and C2B10 clusters formed when the hydrogen atoms are removed from carborane molecules are studied...
Park, Kyungwha, Pederson, Mark R., Baruah, Tunna, Bernstein, Noam, Kortus, Jens, Richardson, Steven L., ...
It has been shown within density-functional theory that in Mn$_{12}$-acetate there are effects due to disorder by solvent molecules and a coupling between vibrational and electronic degrees of...
Electronic structure and magnetic anisotropy for nickel-based molecular magnets (2004)
Park, Kyungwha, Yang, En-Che, Hendrickson, David N.
Recent magnetic measurements on tetra-nickel molecular magnets [Ni(hmp)(ROH)Cl]$_4$, where R=CH$_3$, CH$_2$CH$_3$, or (CH$_2$)$_2$C(CH$_3$)$_3$ and hmp$^-$ is the monoanion of...
Park, Kyungwha, Pederson, Mark R.
To understand the effect of molecular environment on the electronic and magnetic properties of the single-molecule magnet (SMM) Mn$_{12}$, we explore two possible means for adding extra electrons to...
Buendia, Gloria M., Rikvold, Per Arne, Park, Kyungwha, Novotny, M. A.
Using both analytical and simulational methods, we study low-temperature nucleation rates in kinetic Ising lattice-gas models that evolve under two different Arrhenius dynamics that interpose between...
Park, Kyungwha, Baruah, Tunna, Bernstein, Noam, Pederson, Mark R.
For the single-molecule magnet Mn12, Cornia et al. recently proposed that solvent molecules may cause the quantum tunneling that requires a lower symmetry than S4. However, magnetic quantum tunneling...
Properties of low-lying excited manifolds in the Mn12 acetate (2003)
Park, Kyungwha, Pederson, Mark R., Hellberg, C. Stephen
Most experimental data on the single-molecule magnet Mn$_{12}$ acetate have been successfully explained by the assumption that the Mn$_{12}$ acetate has an effective ground-state spin of S=10....
Low-temperature nucleation in a kinetic Ising model with soft stochastic dynamics (2003)
Park, Kyungwha, Rikvold, Per Arne, Buendia, Gloria M., Novotny, M. A.
We study low-temperature nucleation in kinetic Ising models by analytical and simulational methods, confirming the general result for the average metastable lifetime, = A*exp(beta*Gamma) (beta =...
Park, Kyungwha, Pederson, Mark R., Bernstein, Noam
A new type of the single-molecule magnet [Mn_4 O_3 Cl_4 (O_2 CEt)_3(py)_3] forms dimers. Recent magnetic hysteresis measurements on this single-molecular magnet revealed interesting phenomena: an...
DFT calculation of the intermolecular exchange interaction in the magnetic Mn$_4$ dimer (2003)
Park, Kyungwha, Pederson, Mark R., Richardson, Steven L., Aliaga-Alcalde, Nuria, Christou, George
The dimeric form of the single-molecule magnet [Mn$_4$O$_3$Cl$_4$(O$_2$CEt)$_3$(py)$_3$]$_2$ recently revealed interesting phenomena: no quantum tunneling at zero field and tunneling before magnetic...
Defects, Tunneling, and EPR Spectra of Single-Molecule Magnets (2003)
Park, Kyungwha, Novotny, M. A., Dalal, N. S., Hill, S., Rikvold, P. A., Bhaduri, S., ...
We examine theoretically electron paramagnetic resonance (EPR) lineshapes as functions of resonance frequency, energy level, and temperature for single crystals of three different kinds of...
Defects, Tunneling, and EPR Spectra of Single-Molecule Magnets (2003)
Park, Kyungwha, Novotny, M. A., Dalal, N. S., Hill, S., Rikvold, P. A.
We examine theoretically electron paramagnetic resonance (EPR) lineshapes as functions of resonance frequency, energy level, and temperature for single crystals of three different kinds of...
Park, Kyungwha, Novotny, M. A., Rikvold, P. A.
We examine a square-lattice nearest-neighbor Ising quantum ferromagnet coupled to $d$-dimensional phonon baths. Using the density-matrix equation, we calculate the transition rates between...
Park, Kyungwha, Novotny, M. A., Dalal, N. S., Hill, S., Rikvold, P. A.
We examine quantitatively the temperature dependence of the linewidths and line shifts in electron paramagnetic resonance experiments on single crystals of the single-molecule magnets Fe$_8$ and...
Park, Kyungwha, Dalal, N. S., Rikvold, P. A.
We herein estimate the effect of lattice defects on the line shape of electron paramagnetic resonance (EPR) signals from a single crystal of the S=10 single-molecule magnet Mn$_{12}$ with the...
Park, Kyungwha, Novotny, M. A., Dalal, N. S., Hill, S., Rikvold, P. A.
We study theoretically Electron Paramagentic Resonance (EPR) linewidths for single crystals of the molecular magnets Fe$_8$ and Mn$_{12}$ as functions of energy eigenstates $M_s$, frequency, and...
Park, Kyungwha, Novotny, M. A.
We derive a direct connection between Monte Carlo time and physical time in terms of physical parameters, using a quantum Hamiltonian with a $d$-dimensional phonon heat bath interacting with a...
Park, Kyungwha, Novotny, M. A., Dalal, N. S., Hill, S., Rikvold, P. A.
Electron paramagnetic resonance (EPR) measurements on single crystals of the molecular magnets Fe$_8$ and Mn$_{12}$ reveal complex nonlinearities in the linewidths as functions of energy eigenstate,...
Superconducting Phase with Fractional Vortices in the Frustrated Kagome Wire Network at f=1/2 (2000)
Park, Kyungwha, Huse, David A.
In classical XY kagome antiferromagnets, there can be a novel low temperature phase where $\psi^3=e^{i3\theta}$ has quasi-long-range order but $\psi$ is disordered, as well as more conventional...
Park, Kyungwha, Huse, David A.
We investigate the stability of the square vortex lattice which has been recently observed in experiments on the borocarbide family of superconductors. Taking into account the tetragonal symmetry of...