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Solar Energy

What: Our "Full Spectrum Boost Project" focuses on solar cells made of colloidal nanoparticles. Absorption is boosted at low energies by the Intermediate Band process and at high energies by Carrier Multiplication. Our cells transcend QCD: the Quantum Confinement Dilemma. Transport is modeled as ab initio-based Monte Carlo/Marcus hopping or Boltzmann theory. How: LDA, TD-DFT, GW, BSE, Lanczos methods, Molecular Dynamics, Kinetic Monte Carlo

Magnets for Energy and Recording

What: We are exploring the reversal mechanism of hard permanent magnets in order to improve their utility for alternative energy purposes. We study the competition of domain wall propagation and nucleation in sintered and nanostructured rare earth magnets. We are analyzing hard-soft composites.
How: Finite element LLG, FORC analysis: mean field + local corrections, OOMMF, analytic methods in one dimension, elastic rubber band method for barriers

Solar Desalination

What: We have invented photovoltaic desalination. We have provided the proof of concept experimentally. We are performing extensive simulations to analyze the dynamics of the desalination/flushing cycle, from the atomistic scale to simulating individual channels to building an effective medium theory for the device.

How: Finite element hydrodynamics, COMSOL hydrodynamics, effective medium theory

Glassy Systems

What: We are exploring the slow dynamics, the glassy phases and memory and aging effects of spin glasses, dislocation systems and Coulomb glasses. We also analyze the formation of avalanches and their statistics. Using scaling analysis, we research the conditions which give rise to Self Organized Criticality.

How: Parallel tempering and other accelerated Monte Carlo techniques, Scaling analysis

Memristors

What: We are exploring the revolutionary memristor paradigm that promises to redefine the architecture of computers. We study the electronic transport with explicit inclusion of underlying vacancy dynamics. We treat the long range Coulomb interaction with care. We focus on the hysteretic switching phenomena and explore the role of oxide tunneling barriers

How: Molecular Dynamics, Long range interactions


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What’s New

Jan. 2017: Two new graduate students, Chase Hansen and Ben Cohen-Stead decided to join our group. Welcome Chase and Ben!

Nov. 2016: GTZ was invited by the California Energy Commissioner to give a presentation on photovoltaic water desalination at the Energy Commission in Sacramento.

Nov. 2016: Our patent on photovoltaic desalination, with co-inventors Luman Qu and GTZ has just been published by the US Patent and Trademark Office.

Oct. 2016: GTZ gave an invited talk on Spin wave renormalized Finite Element Simulations of Magnetism in the New Orleans FORC-2016 conference.

Jun. 2016: GTZ gave an invited talk on the Transport in Nanoparticle Solar cells at the Santa Fe "Excited State Processes" conference.

Jun. 2015: Giulia Galli, Marton Voros and GTZ published a paper in ACS Nano, entitled "Colloidal Nanoparticles for Intermediate Solar Cells", proposing a new paradigm to realize the exciting promise of Intermediate Band solar cells with a 55% theoretical maximum efficiency.

May 2015: GTZ gave an invited talk on the Mean Field Theory of FORC at the Hysteresis and Magnetic Modeling 2015 conference

Apr. 2015: In collaboration with Harry Radousky at Livermore National Laboratories and the Logan group at Urbana, Luman Qu and GTZ filed a patent application, entitled "Photovoltaic Desalination System"

Jan. 2015: Group alumnus Marton Voros was awarded the prestigious 2015 Aneesur Rahman Fellowship in Computational Physics at Argonne National Laboratory. Congratulations, Marton!

Oct. 2014: GTZ gave the Oct. 28 colloquium at Stanford University

Jun. 2014: Graduate student Luman Qu joined our group from Cambridge, UK. Welcome Luman!

Mar. 2014: Our work on complementary transport channels in Si nanoparticles embedded in a ZnS matrix was on the cover of the Physical Review Letters