TY  - JOUR
A1  - Thierschmann, H
A1  - Arnold, F
A1  - Mittermüller, M
A1  - Maier, L
A1  - Heyn, C
A1  - Hansen, W
A1  - Buhmann, H
A1  - Molenkamp, L W
T1  - Thermal gating of charge currents with Coulomb coupled quantum dots
JF  - New Journal of Physics
N2  - We have observed thermal gating, i.e. electrostatic gating induced by hot electrons. The effect occurs in a device consisting of two capacitively coupled quantum dots. The double dot system is coupled to a hot electron reservoir on one side (QD1), while the conductance of the second dot (QD2) is monitored. When a bias across QD2 is applied we observe a current which is strongly dependent on the temperature of the heat reservoir. This current can be either enhanced or suppressed, depending on the relative energetic alignment of the QD levels. Thus, the system can be used to control a charge current by hot electrons.
KW  - oscillations
KW  - physics
KW  - quantum dot systems
KW  - Coulomb interaction
KW  - thermal gating
KW  - three terminal device
KW  - thermoelectrics
KW  - energy
KW  - thermopower
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-145196
VL  - 17
IS  - 113003
ER  - 
TY  - JOUR
A1  - Kasprzak, J.
A1  - Sivalertporn, K.
A1  - Albert, F.
A1  - Schneider, C.
A1  - Höfling, S.
A1  - Kamp, M.
A1  - Forchel, A.
A1  - Muljarov, E. A.
A1  - Langbein, W.
T1  - Coherence dynamics and quantum-to-classical crossover in an exciton-cavity system in the quantum strong coupling regime
JF  - New Journal of Physics
N2  - Interaction between light and matter generates optical nonlinearities, which are particularly pronounced in the quantum strong coupling regime. When a single bosonic mode couples to a single fermionic mode, a Jaynes-Cummings (JC) ladder is formed, which we realize here using cavity photons and quantum dot excitons. We measure and model the coherent anharmonic response of this strongly coupled exciton-cavity system at resonance. Injecting two photons into the cavity, we demonstrate a \(\sqrt 2\) larger polariton splitting with respect to the vacuum Rabi splitting. This is achieved using coherent nonlinear spectroscopy, specifically four-wave mixing, where the coherence between the ground state and the first (second) rung of the JC ladder can be interrogated for positive (negative) delays. With increasing excitation intensity and thus rising average number of injected photons, we observe spectral signatures of the quantum-to-classical crossover of the strong coupling regime.
KW  - Jaynes-Cummings ladder
KW  - spectral interferometry
KW  - photon
KW  - dot
KW  - spectroscopy
KW  - oscillations
KW  - microcavity
KW  - resonance
KW  - light
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123005
SN  - 1367-2630
VL  - 15
IS  - 045013
ER  -