Özgün, Ege2016-04-182016-04-182016-022016-0218-02-2016http://hdl.handle.net/11693/28916Cataloged from PDF version of thesis.Includes bibliographical references (leaves 54-60).Thesis (Ph. D.): Bilkent University, Department of Physics, İhsan Doğramacı Bilkent University, 2016.Excitonic systems are challenging to deal with both theoretically and experimentally but in return, they offer a very rich physics and exotic features. We will investigate their properties under weak magnetic field and the resultant instabilities reminiscent of Sarma-I and Sarma-II phases. A new type of force in condensed matter physics, emerging due to the presence of the excitonic condensation will be demonstrated via semi-analytical and numerical calculations in two different systems of GaAs double quantum well geometries and layered transition metal dichalcogenide material 1T-TiSe2. Competition of charge-density wave and exciton condensate orders in layered systems will also be discussed in detail and an alternative explanation for the periodic lattice distortions observed in 1T-TiSe2 will be posed.x, 71 leaves : illustrations, charts.Englishinfo:eu-repo/semantics/openAccessExciton condensationCharge-density waves, double quantum wells.Double quantum wellsThesisB012097