Coherent optical spectroscopy of a strongly driven quantum dot.
Quantum dots are typically formed from large groupings of atoms and thus may be expected to have appreciable many-body behavior under intense optical excitation. Nonetheless, they are known to exhibit discrete energy levels due to quantum confinement effects. We show that, like single-atom or single-molecule two- and three-level quantum systems, single semiconductor quantum dots can also exhibit interference phenomena when driven simultaneously by two optical fields. Probe absorption spectra are obtained that exhibit Autler-Townes splitting when the optical fields drive coupled transitions and complex Mollow-related structure, including gain without population inversion, when they drive the same transition. Our results open the way for the demonstration of numerous quantum level-based applications, such as quantum dot lasers, optical modulators, and quantum logic devices.
Xu
Xiaodong
X
H. M. Randall Laboratory of Physics, University of Michigan, Ann Arbor, MI 48109, USA.
Sun
Bo
B
Berman
Paul R
PR
Steel
Duncan G
DG
Bracker
Allan S
AS
Gammon
Dan
D
Sham
L J
LJ