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Halbleiter-Nanostrukturen und -Quantensysteme

Jonathan Finley

Forschungsgebiet

Our group explores a wide range of topics related to the fundamental physics of nanostructured materials and their quantum-electronic and -photonic properties. We study the unique electronic, photonic and quantum properties of materials patterned over nanometer lengthscales and explore how sub-components can be integrated together to realise entirely new materials with emergent properties. This convergence of materials-nanotechnology, quantum electronics and photonics is strongly interdisciplinary, spanning topics across the physical sciences, as well as materials science and engineering.

Adresse/Kontakt

Am Coulombwall 4/I
85748 Garching b. München
+49 89 289 12771
Fax: +49 89 289 12704

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Mitarbeiterinnen und Mitarbeiter

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Ausgeschriebene Angebote für Abschlussarbeiten an der Arbeitsgruppe

Exploring Exciton-Exciton Interactions in Atomically Thin Nanomaterials

Monolayer transition metal dichalcogenides (TMD) are “graphene-like” layered materials consisting of covalently bonded trilayers of atoms held together by weak van der Waals bonds . Unlike graphene that has vanishing bandgap, monolayer TMDs are direct gap semiconductors with bandgaps >2eV.  The weak dielectric screening results in them hosting very strongly bound 2D Wannier-Mott like excitons with binding energies >>kBT at room temperature and radii in the range of a couple of nm.  The excitonic photo-physics of such nanomaterials currently attracts a lot of attention with many key questions like: How do excitons in atomically thin materials interact with their environment? and What is the role of exciton-exciton interactions on the coherence and optical efficiency of such materials? 


This thesis is aimed at particularly capable students who are interested to join us to explore the fascinating photophysics of TMD heterostructures.  In the first part of the thesis you will build-up, test and control an optical fiber based tunable Fabry-Perot cavity formed between an ultralow-roughness mirror fabricated directly on the end facet of an optical fiber [1] and a high-reflectivity Distributed Bragg Reflector onto which the TMD-heterostructure is placed.  The separation between the fiber end facet and the lower DBR mirror will be piezo- stabilized to achieve ultra-high cavity finesse and tuned to controllably vary the frequency of the cavity mode and tune it through the exciton transition of the TMD.  Hereby, the coherent interaction between the cavity field and the exciton will be revealed by the observation of cavity polaritons [2].  Once developed at room temperature, the systems will aim to make measurements with the entire microscope at liquid helium temperatures where the light-matter interactions are much more coherent....  


You should:

(1) Be highly motivated, (2) Be practically minded, (3) Enjoy working with state of the art optics and with control electronics / computer control and be capable of programming (e.g. Labview, C++ , Python) (4) Be willing to work as part of a small team in a dark lab in the summertime....  


You’ll get:


(1) experience of performing sophisticated optical spectroscopy in state-of-the-art laboratories and (2) a sound understand / explore exciton-exciton interactions in TMD-nanomaterials and, hopefully, (3) a nice paper in a journal.


  


[1] D Hunger et al,  New J. Phys. 12 065038, (2010)

[2] S. Dufferwiel et al. Nature Communications 6, 8579 (October 2015)


INTERESTED?  The please E-Mail finley@wsi.tum.de or come by my office for a discussion,. 

 

geeignet als
  • Bachelorarbeit Physik
  • Masterarbeit Physik der kondensierten Materie
Themensteller(in): Jonathan Finley
Nuclear Magnetic Resonance Microscopy

Nuclear Magnetic Resonance Microscopy

Magnetic resonance imaging (NMR/MRI), is one of the most powerful techniques to record three-dimensional images of nearly arbitrary samples. Current devices, such as those found in hospitals, cannot record details smaller than 1mm.  

Our group aims to push MRI to a microscopy technique by improving its spatial resolution down to the sub-nm range, the scale of single atoms. This ambitious goal has recently become a realistic prospect by a new generation of quantum sensors for magnetic fields. They are based on the nitrogen-vacancy (NV) color defect in diamond and could detect fields as small as the NMR signal of a single molecule [1,2].

We are looking for a MSc student to develop the next generation of our chip-scale NMR spectrometers, and to perform experiments on magnetic resonance imaging with a spatial resolution in the nanoscale range. 

Techniques:

* You will learn to fabricate microscale electromagnets in one of our clean rooms, and optimize our fabrication techniques for your project and others. 

* You will design a sensor chip for microscale NMR detection and upgrade software and optics of one of our setups to perform the experiment. 

* You will design, implement and analyze quantum control protocols to record nanoscale MRI images.

[1] T. Staudacher et al., Science 339, 561 (2013)

[2] H.J. Mamin et al., Science 339, 557 (2013)

geeignet als
  • Masterarbeit Physik der kondensierten Materie
  • Masterarbeit Biophysik
  • Masterarbeit Applied and Engineering Physics
Themensteller(in): Friedemann Reinhard

Abgeschlossene und laufende Abschlussarbeiten an der Arbeitsgruppe

Properties of magnetoresistant Sensors in Vortex-Configuration
Abschlussarbeit im Masterstudiengang Physics (Applied and Engineering Physics)
Themensteller(in): Jonathan Finley
Exploring Exciton-Exciton Interactions in Atomically Thin Nanomaterials
Abschlussarbeit im Masterstudiengang Physics (Applied and Engineering Physics)
Themensteller(in): Jonathan Finley
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