Olesia Dmytruk
ContactDepartment of PhysicsUniversity of Basel Klingelbergstrasse 82 CH4056 Basel, Switzerland

Short CV
2016present:  Postdoc in the Condensed Matter Theory & Quantum Computing group of Prof. Klinovaja and Prof. Loss at the University of Basel 
20132016: 
PhD in theoretical physics, Université ParisSaclay, Laboratoire de Physique des Solides. PhD thesis: Quantum Transport in a Correlated Nanostructure coupled to Microwave Cavity (under supervision of Prof. Pascal Simon) 
20112013: 
Master in theoretical physics, Taras Schevchenko National University of Kyiv, Physics
department. Master thesis: Nonstationary Processes of Exciton Condensation in Quantum Wells in External Fields (under supervision of Prof. V. I. Sugakov, Institute for Nuclear Research) 
20072011: 
Bachelor in physics, Taras Schevchenko National University of Kyiv, Physics department. Qualification work: Phase transitions in nonequilibrium systems under nonstationary radiation (under supervision of Prof. V. I. Sugakov, Institute for Nuclear Research) 
Publications
Show all abstracts.1.  Josephson effect in topological superconducting rings coupled to a microwave cavity 
Olesia Dmytruk, Mircea Trif, and Pascal Simon. Phys. Rev. B 94, 115423 (2016)
We theoretically study a onedimensional pwave superconducting mesoscopic ring interrupted by a weak link and coupled inductively to a microwave cavity. We establish an inputoutput description for the cavity field in the presence of the ring, and identify the electronic contributions to the cavity response and their dependence on various parameters, such as the magnetic flux, chemical potential, and cavity frequency. We show that the cavity response is 4π periodic as a function of the magnetic flux in the topological region, stemming from the socalled fractional Josephson current carried by the Majorana fermions, while it is 2π periodic in the nontopological phase, consistent with the normal Josephson effect. We find a strong dependence of the signal on the cavity frequency, as well as on the parity of the ground state. Our model takes into account fully the interplay between the lowenergy Majorana modes and the gapped bulks states, which we show is crucial for visualizing the evolution of the Josephson effect during the transition from the topological to the trivial phase.
 
2.  Outofequilibrium quantum dot coupled to a microwave cavity 
Olesia Dmytruk, Mircea Trif, Christophe Mora, and Pascal Simon. Phys. Rev. B 93, 075425 (2016)
We consider a superconducting microwave cavity capacitively coupled to both a quantum conductor and its electronic reservoirs. We analyze in detail how the measurements of the cavity microwave field, which are related to the electronic charge susceptibility, can be used to extract information on the transport properties of the quantum conductor. We show that the asymmetry of the capacitive couplings between the electronic reservoirs and the cavity plays a crucial role in relating optical measurements to transport properties. For asymmetric capacitive couplings, photonic measurements can be used to probe the finite lowfrequency admittance of the quantum conductor, the real part of which is related to the differential conductance. In particular, when the quantum dot is far from resonance, the charge susceptibility is directly proportional to the admittance for a large range of frequencies and voltages. However, when the quantum conductor is near resonance, such a relation generally holds only at low frequency and for equal tunnel coupling or low voltage. Beyond this lowenergy nearequilibrium regime, the charge susceptibility and thus the optical transmission offer new insights into the quantum conductors since the optical observables are not directly connected to transport quantities. For symmetric lead capacitive couplings, we show that the optical measurements can be used to reveal the KorringaShiba relation, connecting the reactive to the dissipative part of the susceptibility, at low frequency and low bias.
 
3.  Cavity quantum electrodynamics with mesoscopic topological superconductors 
Olesia Dmytruk, Mircea Trif, and Pascal Simon. Phys. Rev. B 92, 245432 (2015)
We study onedimensional pwave superconductors capacitively coupled to a microwave stripline cavity. By probing the light exiting from the cavity, one can reveal the electronic susceptibility of the pwave superconductor. We analyze two superconducting systems: the prototypical Kitaev chain and a topological semiconducting wire. For both systems, we show that the photonic measurements, via the electronic susceptibility, allow us to determine the topological phasetransition point, the emergence of the Majorana fermions, and the parity of their ground state. We show that all of these effects, which are absent in effective theories that take into account the coupling of light to Majorana fermions only, are due to the interplay between the Majorana fermions and the bulk states of the superconductors.
 
4.  Amplification and passing through the barrier of the exciton condensed phase pulse in double quantum wells 
O.I. Dmytruk and V.I. Sugakov. Physica B: Condensed Matter 436, 80 (2014)
The peculiarities and the possibility of a control of exciton condensed pulse movement in semiconductor double quantum wells under the slot in the metal electrode are studied. The condensed phase has been considered phenomenologically with the free energy in LandauGinzburg form taking into account the finite value of the exciton lifetime. It was shown that the exciton condensed phase pulse moves along the slot driven by an external linear potential. If the exciton density is high enough for the formation of the condensed phase then the pulse moves maintaining a constant value of a maximum density during exciton lifetime, while the exciton gas phase pulse diffuses. The penetration of the exciton condensed phase pulse through a barrier and its stopping by the barrier have been studied. Additionally, it was shown that the exciton pulse in the condensed phase can be amplified and recovered after damping by an additional laser pulse. Solutions for the system of excitons in double quantum wells under the slot in the electrode under steady irradiation in the form of bright and dark autosolitons were found.
 
5.  Movement and amplification of exciton condensed phase pulses and interaction between pulses in semiconductor quantum wells 
O.I. Dmytruk and V.I. Sugakov. Physics Letters A 376, 2804 (2012)
Formation and movement of an exciton pulse in an inhomogeneous potential are studied. It is shown that the pulse does not blur and the maximum of the exciton density in the pulse remains constant during the exciton lifetime if the pulse is formed from the condensed phase. The path, traversed by the excitons, can be increased by imposing an additional laser pulse on the system. Thereby, such a system can be used for information transmission over the exciton condensed phase.
