Research Focus

Zoltán Soos, a professor of chemistry, has conducted research at the intersection of chemistry and physics for nearly half a century. His research has focused on organic molecular solids, ion radical and charge transfer salts, neutral-ionic phase transitions, electronic excitations of conjugated polymers, triplet spin excitons and one-dimentional spin systems. Some of these areas have seen numerous applications with the rise of electronic devices over the last three decades. Soos has had a large network of collaborators, from his graduate students to Princeton colleagues, and from Sandia National Laboratories in Albuquerque, N.M., to the University of Parma in Italy and the Indian Institute of Science in Bangalore, India.

Prior to coming to Princeton in 1966, Soos was a National Science Foundation postdoctoral fellow at Stanford. He earned his bachelor's degree in chemistry and physics at Harvard, and he earned his Ph.D. at the California Institute of Technology.

Research Areas
Materials
Theoretical Chemistry
Selected Recent Publications

D'Avino, G.; Girlando, A.; Painelli, A.; Lemee-Cailleau, M.-H.; Soos, Z. G., "Anomalous dispersion of optical phonons at the neutral-ionic transition: Evidence from diffuse x-ray scattering." Physical Review Letters 2007, 99 (15).

Dutton, S. E.; Kumar, M.; Mourigal, M.; Soos, Z. G.; Wen, J. J.; Broholm, C. L.; "Andersen, N. H.; Huang, Q.; Zbiri, M.; Toft-Petersen, R.; Cava, R. J., Quantum Spin Liquid in Frustrated One-Dimensional LiCuSbO4." Physical Review Letters 2012, 108 (18).

Dutton, S. E.; Kumar, M.; Soos, Z. G.; Broholm, C. L.; Cava, R. J., "Dominant ferromagnetism in the spin-1/2 half-twist ladder 334 compounds, Ba3Cu3In4O12 and Ba3Cu3Sc4O12." Journal of Physics-Condensed Matter 2012, 24 (16).

Kumar, M.; Dutton, S. E.; Cava, R. J.; Soos, Z. G., "Spin-flop and antiferromagnetic phases of the ferromagnetic half-twist ladder compounds Ba3Cu3In4O12 and Ba3Cu3Sc4O12." Journal of Physics-Condensed Matter 2013, 25 (13).

Kumar, M.; Ramasesha, S.; Pascal, R. A., Jr.; Soos, Z. G., "Dimerization transition of alkali-TCNQ salts: Charge degrees of freedom near the CDW boundary." Epl 2008, 83 (3).

Kumar, M.; Ramasesha, S.; Soos, Z. G., "Tuning the bond-order wave phase in the half-filled extended Hubbard model." Physical Review B 2009, 79 (3).

Kumar, M.; Ramasesha, S.; Soos, Z. G., "Bond-order wave phase, spin solitons, and thermodynamics of a frustrated linear spin-1/2 Heisenberg antiferromagnet." Physical Review B 2010, 81 (5).

Kumar, M.; Ramasesha, S.; Soos, Z. G., "Density matrix renormalization group algorithm for Bethe lattices of spin-1/2 or spin-1 sites with Heisenberg antiferromagnetic exchange." Physical Review B 2012, 85 (13).

Kumar, M.; Ramasesha, S.; Soos, Z. G., "Quantum Phase Diagram of One-Dimensional Spin and Hubbard Models with Transitions to Bond Order Wave Phases." Croatica Chemica Acta 2013, 86 (4), 407-417.

Kumar, M.; Soos, Z. G., "Decoupled phase of frustrated spin-1/2 antiferromagnetic chains with and without long-range order in the ground state." Physical Review B 2013, 88 (13).

Kumar, M.; Soos, Z. G., "Bond-order wave phase of the extended Hubbard model: Electronic solitons, paramagnetism, and coupling to Peierls and Holstein phonons." Physical Review B 2010, 82 (15).

Kumar, M.; Soos, Z. G., "Spin-parity and broken symmetry in finite spin-1/2 chains with frustrated exchange: Quantum transition from high to low spin." Physical Review B 2012, 85 (14).

Kumar, M.; Soos, Z. G.; Sen, D.; Ramasesha, S., "Modified density matrix renormalization group algorithm for the zigzag spin-1/2 chain with frustrated antiferromagnetic exchange: Comparison with field theory at large J(2)/J(1)." Physical Review B 2010, 81 (10).

Kumar, M.; Topham, B. J.; Yu, R.; Quoc Binh Dang, H.; Soos, Z. G., "Magnetic susceptibility of alkali-tetracyanoquinodimethane salts and extended Hubbard models with bond order and charge density wave phases." Journal of Chemical Physics 2011, 134 (23).

McQueen, T. M.; Ho, D. M.; Cahua, C. J.; Cava, R. J.; Pascal, R. A., Jr.; Soos, Z. G., "Realization of the bond order wave (BOW) phase of extended Hubbard models in Rb-TCNQ(II)." Chemical Physics Letters 2009, 475 (1-3), 44-48.

Mukhopadhyay, S.; Topham, B. J.; Soos, Z. G.; Ramasesha, S., "Neutral and charged excited states in polar organic films: Origin of unusual electroluminescence in tri-p-tolylamine-based hole conductors." Journal of Physical Chemistry A 2008, 112 (31), 7271-7279.

Prodhan, S.; Soos, Z. G.; Ramasesha, S., "Model for triplet state engineering in organic light emitting diodes." Journal of Chemical Physics 2014, 140 (21).

Sissa, C.; Jahani, P. M.; Soos, Z. G.; Painelli, A., "Essential State Model for Two-Photon Absorption Spectra of Polymethine Dyes." Chemphyschem 2012, 13 (11), 2795-2800.

Soos, Z. G., "Identification of dimerization phase transitions driven by Peierls and other mechanisms." Chemical Physics Letters 2007, 440 (1-3), 87-91.

Soos, Z. G.; Kumar, M.; Ramasesha, S.; Pascal, R. A., Jr., "1:1 Alkali-TCNQ salts and the bond order wave (BOW) phase of half-filled linear Hubbard-type models." Physica B-Condensed Matter 2010, 405 (11), S353-S356.

Soos, Z. G.; Mukhopadhyay, S.; Ramasesha, S., "Polar organic films: Transport gap, charge-dipole interaction and electroluminescence of tritolylamine (TTA) derivatives." Chemical Physics Letters 2007, 442 (4-6), 285-288.

Soos, Z. G.; Topham, B. J., "Surface dipole of F4TCNQ films: Collective charge transfer and dipole-dipole repulsion in submonolayers." Organic Electronics 2011, 12 (1), 39-44.

Topham, B. J.; Kumar, M.; Soos, Z. G., "Ionization potentials of crystalline organic thin films: Position dependence due to molecular shape and charge redistribution." Chemical Physics Letters 2010, 493 (4-6), 251-254.

Topham, B. J.; Kumar, M.; Soos, Z. G., "Profiles of Work Function Shifts and Collective Charge Transfer in Submonolayer Metal-Organic Films." Advanced Functional Materials 2011, 21 (10), 1931-1940.

Topham, B. J.; Soos, Z. G., "Ionization in organic thin films: Electrostatic potential, electronic polarization, and dopants in pentacene films." Physical Review B 2011, 84 (16).