title: Anomalous circular polarization of photoluminescence spectra of individual CdSe nanocrystals in an applied magnetic field.
abstract: We study the low-temperature magnetophotoluminescence from individual CdSe nanocrystals. Nanocrystals having a small "bright" exciton fine structure splitting (Delta_{XY}<0.5 meV) exhibit a conventional left and right circularly polarized Zeeman photoluminescence doublet in applied magnetic fields. In contrast, nanocrystals with large Delta_{XY} (>1 meV) show an anomalous magnetophotoluminescence polarization, wherein the lower-energy peak becomes circularly polarized with increasing field, while the higher-energy peak remains linearly polarized. This unusual behavior arises from strong mixing between the absorbing and emitting bright exciton levels due to strong anisotropic exchange interactions.
authors.affiliation: Chemistry Division and the Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: H
authors.initials: H
authors.lastname: Htoon
authors.forename: S A
authors.initials: SA
authors.lastname: Crooker
authors.forename: M
authors.initials: M
authors.lastname: Furis
authors.forename: S
authors.initials: S
authors.lastname: Jeong
authors.forename: Al L
authors.initials: AL
authors.lastname: Efros
authors.forename: V I
authors.initials: VI
authors.lastname: Klimov