@article{40438,
  abstract     = {{<jats:p>Semiconductor microcavities are frequently studied in the context of semiconductor lasers and in application-oriented fundamental research on topics such as linear and nonlinear polariton systems, polariton lasers, polariton pattern formation, and polaritonic Bose–Einstein condensates. A commonly used approach to describe theoretical properties includes a phenomenological single-mode equation that complements the equation for the nonlinear optical response (interband polarization) of the semiconductor. Here, we show how to replace the single-mode equation by a fully predictive transfer function method that, in contrast to the single-mode equation, accounts for propagation, retardation, and pulse-filtering effects of the incident light field traversing the distributed Bragg reflector (DBR) mirrors, without substantially increasing the numerical complexity of the solution. As examples, we use cavities containing GaAs quantum wells and transition-metal dichalcogenides (TMDs).</jats:p>}},
  author       = {{Carcamo, M. and Schumacher, Stefan and Binder, R.}},
  issn         = {{1559-128X}},
  journal      = {{Applied Optics}},
  keywords     = {{Atomic and Molecular Physics, and Optics, Engineering (miscellaneous), Electrical and Electronic Engineering}},
  number       = {{22}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Transfer function replacement of phenomenological single-mode equations in semiconductor microcavity modeling}}},
  doi          = {{10.1364/ao.392014}},
  volume       = {{59}},
  year         = {{2020}},
}

@article{43747,
  abstract     = {{Vortices are topological objects representing the circular motion of a fluid. With their additional degree of freedom, the vorticity, they have been widely investigated in many physical systems and different materials for fundamental interest and for applications in data storage and information processing. Vortices have also been observed in non-equilibrium exciton-polariton condensates in planar semiconductor microcavities. There they appear spontaneously or can be created and pinned in space using ring-shaped optical excitation profiles. However, using the vortex state for information processing not only requires creation of a vortex but also efficient control over the vortex after its creation. Here we demonstrate a simple approach to control and switch a localized polariton vortex between opposite states. In our scheme, both the optical control of vorticity and its detection through the orbital angular momentum of the emitted light are implemented in a robust and practical manner.}},
  author       = {{Meier, Torsten and Ma, Xuekai and Berger, Bernd and Aßmann, Marc and Driben, Rodislav and Schneider, Christian and Höfling, Sven and Schumacher, Stefan}},
  journal      = {{Nature communications}},
  number       = {{1}},
  pages        = {{897}},
  publisher    = {{Nature Publishing Group UK}},
  title        = {{{Realization of all-optical vortex switching in exciton-polariton condensates}}},
  doi          = {{10.1038/s41467-020-14702-5}},
  volume       = {{11}},
  year         = {{2020}},
}

@article{20580,
  author       = {{Ma, Xuekai and Berger, B and Aßmann, M and Driben, R and Meier, Torsten and Schneider, C and Höfling, S and Schumacher, Stefan}},
  issn         = {{2041-1723}},
  journal      = {{Nature Communications}},
  number       = {{1}},
  pages        = {{897}},
  title        = {{{Realization of all-optical vortex switching in exciton-polariton condensates}}},
  doi          = {{10.1038/s41467-020-14702-5}},
  volume       = {{11}},
  year         = {{2020}},
}

@article{20584,
  author       = {{Ren, J and Liao, Q and Huang, H and Li, Y and Gao, T and Ma, Xuekai and Schumacher, Stefan and Yao, J and Bai, S and Fu, H}},
  issn         = {{1530-6992}},
  journal      = {{Nano Letters}},
  number       = {{10}},
  pages        = {{7550--7557}},
  title        = {{{Efficient Bosonic Condensation of Exciton Polaritons in an H-Aggregate Organic Single-Crystal Microcavity.}}},
  doi          = {{10.1021/acs.nanolett.0c03009}},
  volume       = {{20}},
  year         = {{2020}},
}

@article{20585,
  author       = {{Ma, Xuekai and Kartashov, YV and Ferrando, A and Schumacher, Stefan}},
  issn         = {{0146-9592}},
  journal      = {{Optics Letters}},
  number       = {{19}},
  pages        = {{5311--5314}},
  title        = {{{Topological edge states of nonequilibrium polaritons in hollow honeycomb arrays.}}},
  doi          = {{10.1364/ol.405844}},
  volume       = {{45}},
  year         = {{2020}},
}

@article{20587,
  author       = {{Barkhausen, F and Schumacher, Stefan and Ma, Xuekai}},
  issn         = {{0146-9592}},
  journal      = {{Optics Letters}},
  number       = {{5}},
  pages        = {{1192--1195}},
  title        = {{{Multistable circular currents of polariton condensates trapped in ring potentials.}}},
  doi          = {{10.1364/ol.386250}},
  volume       = {{45}},
  year         = {{2020}},
}

@article{20586,
  author       = {{Ma, Xuekai and Kartashov, YV and Kavokin, A and Schumacher, Stefan}},
  issn         = {{0146-9592}},
  journal      = {{Optics Letters}},
  number       = {{20}},
  pages        = {{5700--5703}},
  title        = {{{Chiral condensates in a polariton hexagonal ring.}}},
  doi          = {{10.1364/ol.405400}},
  volume       = {{45}},
  year         = {{2020}},
}

@article{20581,
  author       = {{Pukrop, Matthias and Schumacher, Stefan and Ma, Xuekai}},
  journal      = {{Physical Review B}},
  number       = {{20}},
  pages        = {{205301}},
  publisher    = {{American Physical Society}},
  title        = {{{Circular polarization reversal of half-vortex cores in polariton condensates}}},
  doi          = {{10.1103/PhysRevB.101.205301}},
  volume       = {{101}},
  year         = {{2020}},
}

@article{20583,
  author       = {{Ma, Xuekai and Kartashov, Yaroslav V. and Gao, Tingge and Torner, Lluis and Schumacher, Stefan}},
  journal      = {{Physical Review B}},
  number       = {{4}},
  pages        = {{045309}},
  publisher    = {{American Physical Society}},
  title        = {{{Spiraling vortices in exciton-polariton condensates}}},
  doi          = {{10.1103/PhysRevB.102.045309}},
  volume       = {{102}},
  year         = {{2020}},
}

@article{20578,
  author       = {{Driben, R and Ma, Xuekai and Schumacher, Stefan and Meier, Torsten}},
  issn         = {{0146-9592}},
  journal      = {{Optics Letters}},
  number       = {{6}},
  pages        = {{1327--1330}},
  title        = {{{Bloch oscillations of multidimensional dark soliton wave packets and light bullets}}},
  doi          = {{10.1364/ol.44.001327}},
  volume       = {{44}},
  year         = {{2019}},
}

@article{15851,
  author       = {{Ma, Xuekai and Kartashov, Yaroslav Y and Gao, Tingge and Schumacher, Stefan}},
  issn         = {{1367-2630}},
  journal      = {{New Journal of Physics}},
  title        = {{{Controllable high-speed polariton waves in a PT-symmetric lattice}}},
  doi          = {{10.1088/1367-2630/ab5a9b}},
  volume       = {{21}},
  year         = {{2019}},
}

@unpublished{13340,
  abstract     = {{Spontaneous formation of transverse patterns is ubiquitous in nonlinear
dynamical systems of all kinds. An aspect of particular interest is the active
control of such patterns. In nonlinear optical systems this can be used for
all-optical switching with transistor-like performance, for example realized
with polaritons in a planar quantum-well semiconductor microcavity. Here we
focus on a specific configuration which takes advantage of the intricate
polarization dependencies in the interacting optically driven polariton system.
Besides detailed numerical simulations of the coupled light-field exciton
dynamics, in the present paper we focus on the derivation of a simplified
population competition model giving detailed insight into the underlying
mechanisms from a nonlinear dynamical systems perspective. We show that such a
model takes the form of a generalized Lotka-Volterra system for two competing
populations explicitly including a source term that enables external control.
We present a comprehensive analysis both of the existence and stability of
stationary states in the parameter space spanned by spatial anisotropy and
external control strength. We also construct phase boundaries in non-trivial
regions and characterize emerging bifurcations. The population competition
model reproduces all key features of the switching observed in full numerical
simulations of the rather complex semiconductor system and at the same time is
simple enough for a fully analytical understanding of the system dynamics.}},
  author       = {{Pukrop, Matthias and Schumacher, Stefan}},
  booktitle    = {{arXiv:1903.12534}},
  title        = {{{Externally Controlled Lotka-Volterra Dynamics in a Linearly Polarized  Polariton Fluid}}},
  year         = {{2019}},
}

@unpublished{13347,
  abstract     = {{<jats:p>&lt;div&gt;
			&lt;div&gt;
				&lt;div&gt;
					&lt;p&gt;Molecular doping in conjugated polymers is a crucial process for their application in organic
photovoltaics and optoelectronics. In the present work we theoretically investigate p-type molecu-
lar doping in a series of (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b”]dithiophene)-alt-
4,7-(2,1,3-benzothiadiazole)] (PCPDT-BT) conjugated oligomers with different lengths and three
widely-used dopants with different electron affinities, namely F4TCNQ, F6TCNNQ, and CN6-CP.
We study in detail the molecular geometry of possible oligomer-dopant complexes and its influence
on the doping mechanisms and electronic system properties. We find that the mechanisms of dop-
ing and charge transfer observed sensitively depend on the specific geometry of the oligomer-dopant
complexes. For a given complex different geometries may exist, some of which show transfer of
an entire electron from the oligomer chain onto the dopant molecule resulting in an integer-charge
transfer complex, leaving the system in a ground state with broken spin symmetry. In other ge-
ometries merely hybridization of oligomer and dopant frontier orbitals occurs with partial charge
transfer but spin-symmetric ground state. Considering the resulting electronic density of states both
cases may well contribute to an increased electrical conductivity of corresponding film samples while
the underlying physical mechanisms are entirely different.
&lt;/p&gt;
				&lt;/div&gt;
			&lt;/div&gt;
		&lt;/div&gt;</jats:p>}},
  author       = {{Dong, Chuan-Ding and Schumacher, Stefan}},
  title        = {{{Molecular Doping of PCPDT-BT Copolymers: Comparison of Molecular Complexes with and Without Integer Charge Transfer}}},
  year         = {{2019}},
}

@article{13343,
  author       = {{Vollbrecht, Joachim and Wiebeler, Christian and Bock, Harald and Schumacher, Stefan and Kitzerow, Heinz-Siegfried}},
  issn         = {{1932-7447}},
  journal      = {{The Journal of Physical Chemistry C}},
  number       = {{7}},
  pages        = {{4483--4492}},
  title        = {{{Curved Polar Dibenzocoronene Esters and Imides versus Their Planar Centrosymmetric Homologs: Photophysical and Optoelectronic Analysis}}},
  doi          = {{10.1021/acs.jpcc.8b10730}},
  volume       = {{123}},
  year         = {{2019}},
}

@article{20576,
  author       = {{Ma, Xuekai and Schumacher, Stefan}},
  issn         = {{0031-9007}},
  journal      = {{Physical Review Letters}},
  number       = {{22}},
  publisher    = {{APS}},
  title        = {{{Vortex Multistability and Bessel Vortices in Polariton Condensates.}}},
  doi          = {{10.1103/physrevlett.121.227404}},
  volume       = {{121}},
  year         = {{2018}},
}

@article{13348,
  author       = {{Luk, Samuel M. H. and Lewandowski, P. and Kwong, N. H. and Baudin, E. and Lafont, O. and Tignon, J. and Leung, P. T. and Chan, Ch. K. P. and Babilon, M. and Schumacher, Stefan and Binder, R.}},
  issn         = {{0740-3224}},
  journal      = {{Journal of the Optical Society of America B}},
  number       = {{1}},
  title        = {{{Theory of optically controlled anisotropic polariton transport in semiconductor double microcavities}}},
  doi          = {{10.1364/josab.35.000146}},
  volume       = {{35}},
  year         = {{2018}},
}

@article{13351,
  author       = {{Breddermann, Dominik and Praschan, Tom and Heinze, Dirk Florian and Binder, Rolf and Schumacher, Stefan}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{12}},
  title        = {{{Microscopic theory of cavity-enhanced single-photon emission from optical two-photon Raman processes}}},
  doi          = {{10.1103/physrevb.97.125303}},
  volume       = {{97}},
  year         = {{2018}},
}

@article{13353,
  author       = {{Lewandowski, Przemyslaw and Luk, Samuel M. H. and Chan, Chris K. P. and Leung, P. T. and Kwong, N. H. and Binder, Rolf and Schumacher, Stefan}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  number       = {{25}},
  title        = {{{Directional optical switching and transistor functionality using optical parametric oscillation in a spinor polariton fluid}}},
  doi          = {{10.1364/oe.25.031056}},
  volume       = {{25}},
  year         = {{2017}},
}

@article{13354,
  author       = {{Luk, S. M. H. and Kwong, N. H. and Lewandowski, P. and Schumacher, Stefan and Binder, R.}},
  issn         = {{0031-9007}},
  journal      = {{Physical Review Letters}},
  number       = {{11}},
  title        = {{{Optically Controlled Orbital Angular Momentum Generation in a Polaritonic Quantum Fluid}}},
  doi          = {{10.1103/physrevlett.119.113903}},
  volume       = {{119}},
  year         = {{2017}},
}

@article{13364,
  author       = {{Kwong, N H and Tsang, C Y and Luk, Samuel M H and Tse, Y C and Chan, Chris K P and Lewandowski, P and Leung, P T and Schumacher, Stefan and Binder, R}},
  issn         = {{0031-8949}},
  journal      = {{Physica Scripta}},
  title        = {{{Optical switching of polariton density patterns in a semiconductor microcavity}}},
  doi          = {{10.1088/1402-4896/aa58f6}},
  year         = {{2017}},
}