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Dr. Lin Chen

Photo von Dr. Lin Chen.
Phone
+49 89 289-12406
Room
2035
E-Mail
lin0.chen@tum.de
Links
Page in TUMonline
Group
Experimental Physics of Functional Spin Systems

Courses and Dates

Offered Bachelor’s or Master’s Theses Topics

Aufbau eines Spektrometers für ferromagnetische Resonanz für Frequenzen bis 65 GHz

In dieser Arbeit soll ein neues Spektrometer für Messungen mit Methoden der ferromagnetischen Resonanz im Frequenzbereich zwischen 10 - 65 GHz aufgebaut und getestet werden.

suitable as
  • Bachelor’s Thesis Physics
Supervisor: Christian Back
Nachweis von Spin-Orbit-Torques mit Hilfe eines stehenden Spinwellenmusters
Current-induced spin-orbit torques (SOTs) in ferromagnet/nonmagnetic metal heterostructures open vast possibilities to design spintronic devices to store, process, and transmit information in a simple architecture. It is a central task to search for efficient SOT devices, and to quantify the magnitude as well as the symmetry of current-induced spin-orbit magnetic fields (SOFs). Here, we will evaluate an approach to determine the SOFs based on magnetization dynamics by means of time-resolved magneto-optic Kerr microscopy. A microwave current in a narrow Fe/GaAs (001) stripe generates an Oersted field as well as SOFs due to the reduced symmetry at the Fe/GaAs interface, and excites standing spin wave (SSW) modes because of the lateral confinement. Due to their different symmetries, the SOFs and the Oersted field generate distinctly different mode patterns. Thus, it is possible to determine the magnitude of the SOFs from an analysis of the shape of the SSW patterns. Specifically, this method, which is conceptually different from previous approaches based on line shape analysis, is phase independent and self-calibrated. It can be used to measure the current-induced SOFs in other material systems, e.g., ferromagnetic metal/nonmagnetic metal heterostructures.
suitable as
  • Master’s Thesis Condensed Matter Physics
Supervisor: Christian Back
Wechselwirkung zwischen Spin-Orbit-Torque und supraleitenden Zuständen in Ni/Bi Heterostrukturen
Durch Magneto-Transport Messungen bei tiefen Temperaturen können sogenannte Spin-Orbit-Torques detektiert werden, die ausgenutzt werden können um die Magnetisierung von dünnen Filmen zu manipulieren. In diesem Projekt sollen Kombinationen aus ferromagnetischen Schichten und Supraleitern untersucht werden.
suitable as
  • Bachelor’s Thesis Physics
Supervisor: Christian Back
Zeitaufgelöste Messung des Umschaltprozesses für in der Ebene magnetisierte mikrostrukturierte Elemente
The demonstration of magnetization switching induced by spin-orbit torques in a ferromagnetic metal (FM)/heavy metal (HM) bilayer has attracted tremendous attention due to possible application in magnetic random access memories (MRAM). Typically, an in-plane current sent through the heavy metal layer (e.g. Pt) gives rise to a spin accumulation at the FM/HM interface due to the spin Hall effect. The spin accumulation acts on the ferromagnet (e.g. Co) via the spin transfer torque effect and leads to magnetization dynamics and, ideally, to switching. In this Master thesis, we will use time resolved magneto-optical Kerr microscopy (TRMOKE), which is a time and spatially resolved technique, to trace the switching dynamics of an in-plane magnetized ferromagnetic metal. The following points will be addressed: 1) The Co/Pt thin films will be patterned to micrometer-size devices by using a by mask-free laser writer or by electron-beam lithography. 2) Time and spatially resolved magnetization dynamics will be measured by TRMOKE. 3) Finally, the experimental data will be compared to theory.
suitable as
  • Master’s Thesis Condensed Matter Physics
Supervisor: Christian Back
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