Dr. Alexander Ako Khajetoorians
PGI Lecture Hall, Building 04.8, 2nd floor, Room 365
- 09.May.2014 11:00
Probing the magnetic nature of a single atom
An ultimate goal in magnetic-based information technology, is the realization of storage and processing with single atom spins. With the development of scanning tunneling microscopy at ultra-low temperatures and in magnetic fields, two complementary methods, namely spin-polarized scanning tunneling spectroscopy (SP-STS)  and inelastic STS (ISTS) [2-3], can address single spins at the atomic scale. While SP-STS reads out the projection of the impurity magnetization, ISTS detects the excitations of this magnetization as a function of an external magnetic field. They are thus the analogs of magnetometry and spin resonance measurements pushed to the single atom limit. We have recently demonstrated that it is possible to reliably combine single atom magnetometry with an atom-by-atom bottom-up fabrication to realize complex atomic-scale magnets with tailored properties [4-5]. In this talk, I will address recent developments in probing the spin excitations and magnetization curves of single and coupled atoms on a multitude of non-magnetic surfaces, and discuss the both the current fundamental understandings and technological applicability of single atomic spins. Moreover, I will discuss investigations of the magnetization dynamics  of coupled spins, and how the relaxation is affected by processes like quantum tunneling and spin-transfer torque.
 A.A.K., et al. , PRL, 106, 037205 (2011);  A. J. Heinrich, et al. , Science, 306, 466 (2004);  A.A.K, et al. ,Nature, 467, 1084 (2010);  A.A.K., et al., Nature Physics, 8, 497 (2012)  A.A.K., et al., Science, 332, 1062 (2011),  A.A.K., et al, Science, 339, 55 (2013)
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