Research projects in Eric Jeckelmann's group

Doctoral research projects

Current projects

  • Yasemin Ergün, Phase transitions in quantum wires on substrates
  • Gökmen Polat, Numerical investigations of correlated ladder models for doped Mott and charge transfer insulators

 

Completed projects

DFG Research Unit 1807

Advanced Computational Methods for Strongly Correlated Quantum Systems

Project “Advanced wave-function based methods for electron-phonon coupled systems”

The main goal of this project is the development of efficient and versatile computational methods for studying correlated low-dimensional quantum systems with strongly fluctuating bosonic degrees of freedom. In addition, we plan to adapt and test our algorithms on a broad variety of timely problems from condensed matter physics, mostly related to electron-phonon systems. These applications include phase transitions and local entanglement entropy, nonequilibrium and dissipative transport through electron-phonon coupled nanostructures, time-resolved spectroscopy and photoinduced phase transitions in quasi-one-dimensional materials, as well as spin transport in spin-phonon coupled models.

This project is carried out in collaboration with Prof. Dr. Fabian Heidrich-Meisner from the University of Göttingen.

Publications

DFG Research Unit 1700

Metallic nanowires on the atomic scale

Project “Embedded one-dimensional electron-phonon systems”

The aim of this project is to gain a better understanding of one-dimensional physics in atomic wires on surfaces. These systems can be regarded as two-dimensional arrays of weakly-coupled chains with interacting electron and phonon degrees of freedom which are embedded in a three-dimensional environment. Our investigations are based on effective models for the low-energy properties of atomic wires on substrates. We use well-established methods such as mean-field approximations, bosonization, and the density-matrix renormalization group.

We generalize the theory of the Peierls transition driven by the coupling between electrons and lattice distortions to the grand-canonical  ensemble to take into account the underlying substrate. We also examine the influence of the substrate and the inter-wire coupling on the Luttinger liquid properties of metallic wires. Finally, we investigate the occurence of quasi-one-dimensional long-range order in the wire system due to the coupling to the substrate.

Publications

School for Contacts in Nanosystems

Project “Electronic correlations and quantum dynamics in ultrathin nanowires”

This project is a theoretical study of quantum effects and electronic correlations in the transport and spectral properties of ultrathin quantum wires in contact with an environment (metallic leads and heat bath). The wires and their environment are represented by electron-phonon lattice models which are investigated with various, mostly numerical methods such as the density-matrix renormalization group and the time-evolving block decimation.

Publications