de | en

Dr. Mark Kartsovnik

Photo von Dr. Mark Kartsovnik.
Telefon
+49 89 289-14223
Raum
E-Mail
gu27vih@mytum.de
Links
Homepage
Visitenkarte in TUMonline
Arbeitsgruppe
Technische Physik
Zusatzinfo
WMI, Zimmer 132 (1. OG)

Ausgeschriebene Angebote für Abschlussarbeiten

High-field magnetotransport in an organic superconductor in proximity to the quantum spin-liquid Mott-insulating state

One of topical issues of the modern condensed matter physics is the interplay between superconducting and insulating instabilities of the normal metallic state in materials with strong electronic correlations. Organic metals and superconductors, thanks to their high crystal quality, simple conduction bands, and a great diversity of electronic states, offer a perfect laboratory for studying fundamental problems of the correlated electron physics. A member of the κ-(ET)2X family to be studied in this Master thesis is believed to represent a novel state of matter, quantum spin liquid at ambient pressure. Under a moderate pressure of about 3 kbar the material becomes metallic and superconducting.

The aim of the work is to trace the evolution of the electronic properties, particularly, of correlation effects, in close proximity to the metal-insulator phase boundary. The position with respect to the phase boundary will be precisely tuned by applying quasi-hydrostatic pressure. Magnetoresistance and especially its quantum oscillations in strong magnetic fields will be used to probe the electronic properties of the system. Observation of the oscillations requires sufficiently low temperatures which will be achieved by use of a 3He cryostat (down to 0.4 K) and of a 3He-4He dilution refrigerator (down to below 100 mK). A part of the experiment will be done at the European Magnetic Field Laboratory in steady fields up to 30 T or in pulsed fields up to 80 T. The experimental results will be analyzed in comparison with recent theoretical predictions of correlation effects and violations of the Fermi-liquid behavior in proximity to the spin-liquid Mott-insulating state.

Physics: Correlated electron systems; metal-insulator transition; magnetic quantum oscillations; unconventional superconductivity.

Techniques: Strong magnetic fields; high pressures; cryogenic (liquid 4He; 3He; dilution fridge) techniques; high-precision magnetoresistance measurements.

Contact person: Mark Kartsovnik (mark.kartsovnik@wmi.badw.de)

geeignet als
  • Masterarbeit Physik der kondensierten Materie
  • Masterarbeit Applied and Engineering Physics
Themensteller(in): Rudolf Gross
Interaction between magnetic and conducting subsystems in molecular antiferromagnetic superconductors

Multifunctional materials combining nontrivial conducting and magnetic properties are one of hot topics in the modern condensed matter physics. Prominent examples are charge transfer salts of the organic donor BETS with anions containing a transition metal. They represent perfect multilayer structures of conducting and magnetic subsystems separated on a nanometer scale. The interplay between the two subsystems results in a variety of electronic and magnetic ground states depending on subtle chemical substitutions as well as on external magnetic field and pressure. The goal of this master thesis is a quantitative study of the interaction between the itinerant electrons and localized spins in the antiferromagnetic superconductors (BETS)2FeX4 with X = Cl, Br. To this end, comparative measurements of quantum oscillations in the magnetoresistance and magnetization will be carried out at strong magnetic fields, at temperatures down to 0.4 K. The results will be analyzed in terms of the exchange field dependent spin-splitting effect in a quasi-two-dimensional metal.

Physics: Correlated electronic systems; magnetic ordering and superconductivity; magnetic quantum oscillations.

Techniques: Strong magnetic fields; magnetotransport; magnetic torque; cryogenic (liquid 4He and 3He) techniques.

Contact person: Mark Kartsovnik (mark.kartsovnik@wmi.badw.de)

geeignet als
  • Masterarbeit Physik der kondensierten Materie
  • Masterarbeit Applied and Engineering Physics
Themensteller(in): Rudolf Gross
Nach oben