VSI seminar: Richard J. Mawhorter

Speaker:
Richard J. Mawhorter, Pomona College, Claremont, CA, US

Title:
Just Chillin’? Cool(able) Cousins BaF & YbF and YbX Friends

Abstract:
Ytterbium’s 14 f-electrons fill the 4f lanthanide shell so Yb behaves chemically like barium, with vertical Franck-Condon factors in molecules like YbF and BaF that greatly facilitate laser cooling.  With odd numbers of electrons, both have open shell structures with states conducive to parity nonconservation (PNC) studies.  Yb has the further advantage of being significantly heavier, which also aids in this regard.  But these 4f-electrons can easily substitute for the 6s electrons usually involved in forming bonds, and these overlapping molecular electronic states can cause serious complications.  Striving to understand these has prompted studies in ostensibly simpler closed shell YbO in preparation for characterizing even more exotic YbAg.  Both experimental and theoretical steps towards solving the resulting riddles will be discussed.