title: Level anticrossing of impurity states in semiconductor nanocrystals.
abstract: The size dependence of the quantized energies of elementary excitations is an essential feature of quantum nanostructures, underlying most of their applications in science and technology. Here we report on a fundamental property of impurity states in semiconductor nanocrystals that appears to have been overlooked--the anticrossing of energy levels exhibiting different size dependencies. We show that this property is inherent to the energy spectra of charge carriers whose spatial motion is simultaneously affected by the Coulomb potential of the impurity ion and the confining potential of the nanocrystal. The coupling of impurity states, which leads to the anticrossing, can be induced by interactions with elementary excitations residing inside the nanocrystal or an external electromagnetic field. We formulate physical conditions that allow a straightforward interpretation of level anticrossings in the nanocrystal energy spectrum and an accurate estimation of the states' coupling strength.
authors.affiliation: 1] ITMO University, 49 Kronverksky Avenue, 197101 Saint Petersburg, Russia [2] Monash University, Clayton Campus, Victoria 3800, Australia.
authors.forename: Anvar S
authors.initials: AS
authors.lastname: Baimuratov
authors.affiliation: 1] ITMO University, 49 Kronverksky Avenue, 197101 Saint Petersburg, Russia [2] Monash University, Clayton Campus, Victoria 3800, Australia.
authors.forename: Ivan D
authors.initials: ID
authors.lastname: Rukhlenko
authors.affiliation: ITMO University, 49 Kronverksky Avenue, 197101 Saint Petersburg, Russia.
authors.forename: Vadim K
authors.initials: VK
authors.lastname: Turkov
authors.affiliation: ITMO University, 49 Kronverksky Avenue, 197101 Saint Petersburg, Russia.
authors.forename: Irina O
authors.initials: IO
authors.lastname: Ponomareva
authors.affiliation: ITMO University, 49 Kronverksky Avenue, 197101 Saint Petersburg, Russia.
authors.forename: Mikhail Yu
authors.initials: MY
authors.lastname: Leonov
authors.affiliation: Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
authors.forename: Tatiana S
authors.initials: TS
authors.lastname: Perova
authors.affiliation: Dublin Institute of Technology, Dublin 8, Ireland.
authors.forename: Kevin
authors.initials: K
authors.lastname: Berwick
authors.affiliation: ITMO University, 49 Kronverksky Avenue, 197101 Saint Petersburg, Russia.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Baranov
authors.affiliation: ITMO University, 49 Kronverksky Avenue, 197101 Saint Petersburg, Russia.
authors.forename: Anatoly V
authors.initials: AV
authors.lastname: Fedorov