Electron-Phonon Interaction and Disorder: Nanoscale Interference in Transport Phenomena Andrei Sergeyev, SUNY at Buffalo, DMR Thermomagnetic vortex transport: transport entropy revisited Main publications on fundamental problems: 1. A. Sergeev, M. Reizer, and V. Mitin, Europhys. Letters 92, (2010). 2. A. Sergeev, M. Reizer, and V. Mitin, Phys. Rev. Lett. 106, (2011) Problem formulation: (i) Energy transformations due to interactions; (ii) Microscopic definition of the heat current for interacting electrons; (iii) Thermomagnetic coefficients: interaction effects and Onsager relations. In order to verify the conservation of energy, we must be careful that we have not put any in or taken any out. Second, the energy has a large number of different forms… Feynman Lectures on Physiscs Transport entropy, S d, defines both the thermal force, pushing a vortex along the temperature gradient in the Nernst effect and the thermal energy, transferred by a vortex in the Ettingshausen effect. All current theories associate the main contribution to S d with the electromagnetic energy of supercurrents circulating around vortex cores. We prove that supercurrents around cores neither produce the net force due to the temperature gradient, nor participate in the heat transport. Being consistent with the London concept and Onsager relation, our approach naturally explains the absence of the thermomagnetic effects in a system of Josephson vortices in SIS junctions. The revised theory (solid line in Fig) is in very good agreement with the measured transport entropy, in particular with data of Solomon and Otter,1967, (see Fig). These data presented in many textbooks have not been explained for many years. Onsager relations for the thermomagnetic coefficients Magnetization currents transfer the electric charge in the Nernst effect, but they do not transfer the thermal energy in the Ettingshausen effect; The Kubo formula gives directly the Ettingshausen coefficient without any additional corrections due to magnetization currents; In the Fermi liquid, thermomagnetic coefficients are proportional to the square of the particle-hole asymmetry.

Applications of Basic Research to Nanoscale Engineering of Electron Processes for Energy Detection and Conversion Andrei Sergeyev, SUNY at Buffalo, DMR Novel approach to design quantum dot solar cells leads to 50% improvement in efficiency Outreach: New courses and a textbook on quantum mechanical nanoscale engineering Hot electron nanobolometers for detection of THz quanta K.A. Sablon, J.W. Little, V. Mitin, A. Sergeev, N. Vagidov, and K. Reinhardt, “Strong enhancement of solar cell efficiency due to quantum dots with built-in charge,” Nano Letters, 11, 2311 (2011). B.S. Karasik, A. Sergeev, and D. Prober, “Nanobolometers for THz photon detection,” IEEE Trans. on Terahertz Science & Technology, Inaugural Issue (2011). Top: A crossectional view of the nano-HEB detector. A low-TC TES device is fabricated on of the solid dielectric substrate between superconducting contacts (S) preventing diffusion of the thermal energy. Far-IR radiation couples to the TES through a planar antenna or a waveguide. Bottom: The energy diagram showing the energy gap in the contacts that enables Andreev reflection. The energy gap in the TES is zero since it operates in the resistive state.