Hungarian Academy of Sciences, Hungary
Title: Nonlinear surface plasmon assisted electron pairing in gold at room temperature
Norbert Kroó Former General Secretary and Vice-President of the Hungarian Academy of Sciences (HAS), founding director of the Research Institute for Solid State Physics and Optics of HAS. He first used nuclear methods in condensed matter studies and later turned to laser physics and quantum optics, surface plasmon optics being his main concern. He has published about 300 scientific papers and is the owner of 40 patents. He has worked in several countries, and with such outstanding scientists as Herbert Walter and Alexander Prokhorov. He is the former president of the European Physical Society and president of the EötvösLoránd Physical Society for a second term. Member or honorary doctor of several distinguished scientific institutions including the Scientific Council of the European Research Council, and has received awards from many states and their academies. His latest decorations are: the Wallis E. Lamb Award for Laser Physics and Quantum Electronics (USA), the Commander of the Order of the Lion (Finland), Honorary Member of the European Physical Society.. In late 2011 he was raised by popular vote to the status of Prima Primissima in the field of Science.
Strong electromagnetic field of femtosecond Ti:Sa lasers has been used to excite surface plasmons (SPO) in gold films at room temperature in the Kretschmann geometry. Experimental investigations were carried out using a surface plasmon near field scanning tunneling microscope, measuring its response toexcitations at SPO hot spots on the gold surface. Furthermore, the spectra of photoelectrons, liberated by multi-plasmon absorption, have also been measured by a time-of-flight spectrometer. In both cases new type of anomalies in both the STM and electron TOF signals have been measured in the same laser intensity range.The existence of these anomalies may be qualitatively understood, by using an intensity-dependent effective electron-electron scattering potential, derived earlier in a different context. In this theoretical work, an effective attraction potential has been predicted in the presence of strong inhomogeneous radiation fields, leading to electron pairing.