2018/01/01 by Kuzmenko, Igor, Kuzmenko, Tanya, Avishai, Yshai
#Atomic Physics (physics.atom-ph) #FOS: Physical sciences #Quantum Gases (cond-mat.quant-gas) #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.1801.00482
The relevance of magnetic impurity problems in cold atom systems depends crucially on the nature of exchange interaction between itinerant fermionic atoms and a localized impurity atom. In particular, Kondo physics occurs only if the exchange interaction is anti-ferromagnetic, and strong enough to yield high enough Kondo temperature (TK/TF ≥ 0.1). Focusing, as an example, on the experimentally accessible system of ultra-cold 173Yb atoms, it is shown that the sign and strength of an exchange interaction between an itinerant Yb(1S0) atom and a trapped Yb(3P0) atom can be optically controlled. Explicitly, as the light intensity increases (from zero), the exchange interaction changes from ferromagnetic to anti-ferromagnetic. When the light intensity is just below a singlet Feshbach resonance, the singlet scattering length aS is large and negative, and the Kondo temperature increases sharply.