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Halbleiter-Nanostrukturen und -Quantensysteme

Prof. 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

Mitarbeiterinnen und Mitarbeiter der Arbeitsgruppe

Professor

Sekretariat

Wissenschaftlerinnen und Wissenschaftler

Andere Mitarbeiterinnen und Mitarbeiter

Lehrangebot der Arbeitsgruppe

Lehrveranstaltungen mit Beteiligung der Arbeitsgruppe

Titel und Modulzuordnung
ArtSWSDozent(en)Termine
Nanofabrication and Nanoanalytics
Zuordnung zu Modulen:
VO 2 Koblmüller, G. Di, 09:30–11:00, ZEI 0001
sowie einzelne oder verschobene Termine
Semiconductor Quantum Photonics
Zuordnung zu Modulen:
VO 2 Müller, K. Do, 12:00–14:00, WSI 101S
Aktuelle Themen der Halbleiter-Quantenphotonik
Zuordnung zu Modulen:
HS 2 Finley, J.
Mitwirkende: Müller, K.
Exercise to Nanofabrication and Nanoanalytics
Zuordnung zu Modulen:
UE 1
Leitung/Koordination: Koblmüller, G.
Termine in Gruppen
Übung zu Halbleiter-Quantenphotonik
Zuordnung zu Modulen:
UE 1 Müller, K.
FOPRA-Versuch 01: Ballistischer Transport (Flippern mit Elektronen)
Zuordnung zu Modulen:
PR 1 Finley, J.
Mitwirkende: Becker, J.
FOPRA-Versuch 14: Optische Absorption
Zuordnung zu Modulen:
PR 1 Finley, J.
Mitwirkende: Müller, K.
FOPRA-Versuch 15: Quanteninformation in Stickstoff-Fehlstellen-Zentren in Diamant
Zuordnung zu Modulen:
PR 1 Finley, J.
Mitwirkende: Braunbeck, G.
FOPRA-Versuch 24: Feldeffekt-Transistor (MOSFET)
Zuordnung zu Modulen:
PR 1 Finley, J.
Mitwirkende: Flassig, F.
FOPRA-Versuch 45: Optische Eigenschaften von Halbleiter-Quantenfilmen
Zuordnung zu Modulen:
PR 1 Finley, J.
Mitwirkende: Simmet, T.
Munich Physics Colloquium
Zuordnung zu Modulen:
KO 2 Finley, J. Märkisch, B. Mo, 17:15–19:00, PH HS2
Mo, 17:15–19:00
sowie Termine in Gruppen
Repetitorium zu Aktuelle Themen der Halbleiter-Quantenphotonik
Zuordnung zu Modulen:
RE 2
Leitung/Koordination: Finley, J.
Schottky-Seminar
Diese Lehrveranstaltung ist keinem Modul zugeordnet.
SE 2 Finley, J. Holleitner, A. Sharp, I. Stutzmann, M. Di, 17:15–18:15, WSI 101S

Ausgeschriebene Angebote für Abschlussarbeiten an der Arbeitsgruppe

Characterization of Photonic Microstructures - Comparison of theory and experiment

The project

Infrared (IR) spectroscopy is used to identify many chemical substances. It is an established analytical method, but it faces one limitation: sensitivity. Measurements with low concentrations can therefore be difficult, which disqualifies IR for certain applications. The TUM start-up IRUBIS is tackling this issue and found that photonic microstructures on the surface of the sample carrier can lead to a signal enhancement. The aim of this thesis will be to analyze how the design of the structures influences this effect.

 

Your tasks.

  • Conducting measurements
  • Comparing data and simulation
  • Proposing new designs for the photonic structures

 

What we expect!

  • Motivation to work practically on an application-oriented thesis
  • A high degree of independence
  • Ability to work consistent and precise

 

What will you learn?

  • Simulation of photonic microstructures
  • Statistic evaluation of measurement results
  • Deep understanding of microstructure fabrication

 

Interested? 

Send your application directly to Lorenz.Sykora@tum.de, Cc Jonathan.Finley@wsi.tum.de. Please include a cv and a short motivational letter in one pdf file. Starting date: flexible

geeignet als
  • Bachelorarbeit Physik
Themensteller(in): Jonathan Finley
Growth and characterization of high-mobility InAsSb nanowire field effect transistors

At the Walter Schottky Institute (WSI-TUM) we currently conduct an extensive research program on the growth and fabrication of high mobility III-V semiconductor based nanowire FET devices. One of the possible applications of such nanoscale devices is their integration onto CMOS-compatible silicon platform and thereby pave the way for next generation ultrascaled nanoelectronic switches in future consumer electronics or thermoelectric energy conversion systems.

An important step towards high mobility nanowire-FET devices is the development of suitable high-mobility materials and transforming them into nanostructured devices for transport experiments, where the respective charge carrier transport and scattering processes need to be explored. The goal of this M.Sc. project is to explore the novel III-As-Sb nanowire materials (such as InAsSb) as a potentially new high charge carrier mobility system with simultaneously large spin-orbit interaction.

Interacting closely with two PhD students you will be designing the proper InAsSb nanowire materials  by molecular beam epitaxy (MBE) and further transform these into 2- or 4-terminal nanowire-FET devices using advanced nanolitho­graphy methods in state-of-the art cleanroom facilities. The FET devices should be then characterized with respect to their alloy composition, carrier density, channel length and surface passivation schemes in order to identify different regimes of transport (ballistic vs. diffusive) in temperature-dependent electrical transport spectroscopy. Furthermore, magnetotransport measurements will complement these investigations to gain insights also into quantum interference effects during diffusive transport.

In this thesis, you will be closely working with several other student members in the Nanowire Group at WSI, led by PD Dr. Gregor Koblmueller. Experience in the area of clean room fabrication, nanoanalytics or (nano)electronics, as well as experience using Matlab is a benefit, but secondary to motivation and commitment. Applications should be sent to Gregor.Koblmueller@wsi.tum.de, Daniel-Ruhstorfer@wsi.tum.de, or Sergej.Fust@wsi.tum.de . Please include your CV, a copy of your Bachelor Thesis and a transcript of your grades (Bachelor & Master).

geeignet als
  • Masterarbeit Applied and Engineering Physics
Themensteller(in): Gregor Koblmüller
Improving the coherence properties of a quantum sensor
Our quantum sensor of choice, the nitrogen-vacancy center in diamond, is on its way to become the world's smallest MRI scanner. It could give a 3D image of a single bio molecule while simultaneously resolving the chemical components. One limiting problem on this way is the reliable preparation of nitrogen-vacancy centers with long coherence times. We provide a state-of-the art measurement setup and a handful of ideas how to approach this task. We are looking for an enthusiastic student to try several preparation approaches and to perform quantum measurements on the coherence properties of the resulting single quantum sensors. Favorable personality qualities: interest in quantum information science, fun with handicrafts and no fear of software (python)

geeignet als
  • Bachelorarbeit Physik
Themensteller(in): Friedemann Reinhard
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
Probing single and multiple photons with modular superconducting nanowire detectors

Within the last years, superconducting single photon detectors (SSPDs) have proven to be one of the most versatile detectors for visible to infrared wavelengths. They outperform other single photon detectors in terms of detection efficiency (ca 90%), timing resolution (<10ps) and dark count rates (<1cps) and can be modified to detect the number of photons simultaneously hitting the detector (photon-number resolution, PNR) [1]. They can be integrated into on-chip photonic circuits, making them highly promising for future chip-based optical quantum applications.

In this project we aim at adding photon-number resolving capabilities to optical waveguide-integrated SSPDs to detect multi-photon states in optical cavities. We will use established techniques to sputter thin NbTiN and WSi superconducting films and pattern them using e-beam lithography to fabricate the superconducting detectors. These detectors will be tested and characterised at cryogenic temperatures in an optical microscopy setup to probe the fundamental detection mechanisms. We will implement a pixel-based photon number resolving technique and study the interaction of these pixels on the picosecond timescale using ultrafast lasers both in the visible as well as in the infrared regime. 

 

During the project, you will work in close collaboration with a team of Ph.D. students and postdocs, therefore, teamwork is crucial on this project. Some experience in the areas of optics, electronics, programming or cleanroom fabrication will be beneficial, but secondary to your personal motivation and commitment to this fascinating project. You will gain skills and knowledge and probably become an expert in various scientific research tasks, including but not limited to thin-film deposition techniques, nanoscale cleanroom fabrication and state-of-the-art electro-optical measurements at cryogenic temperatures.

 

[1] F. Natarajan et al. Supercond. Sci. Technol. 25 063001 (2012)

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 understanding of the physics of superconducting thin films and quantum light detectors and, hopefully, (3) a nice paper in a journal.

geeignet als
  • Masterarbeit Physik der kondensierten Materie
  • Masterarbeit Applied and Engineering Physics
Themensteller(in): Jonathan Finley

Abgeschlossene und laufende Abschlussarbeiten an der Arbeitsgruppe

Spectroscopy of localized interlayer excitons in van-der-Waals heterostructures
Abschlussarbeit im Masterstudiengang Physics (Applied and Engineering Physics)
Themensteller(in): Jonathan Finley
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