FOPRA Experiment 16: Josephson Effects in Superconductors (AEP, KM, QST-EX)
Course 0000100016 in SS 2024
General Data
| Course Type | practical training |
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| Semester Weekly Hours | 1 SWS |
| Organisational Unit | Technical Physics |
| Lecturers |
Kedar Honasoge Wun Kwan Yam Responsible/Coordination: Rudolf Gross |
| Dates |
Assignment to Modules
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PH0030: Fortgeschrittenenpraktikum für Bachelorstudierende / Advanced Lab Course for B.Sc. Students
This module is included in the following catalogs:- Mandatory Modules in Bachelor Programme Physics (5th Semester, Specialization AEP)
- Mandatory Modules in Bachelor Programme Physics (5th Semester, Specialization BIO)
- Mandatory Modules in Bachelor Programme Physics (5th Semester, Specialization KM)
- Mandatory Modules in Bachelor Programme Physics (5th Semester, Specialization KTA)
- PH1030: Fortgeschrittenenpraktikum für Masterstudierende / Advanced Lab Course for Master Students
- PH1034: Fortgeschrittenenpraktikum (QST) / Advanced Practical Training (QST)
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PH9130: Physikalisches Fortgeschrittenenpraktikum für Lehramtsstudierende / Advanced Lab Course in Physics for M.Ed. Students
This module is included in the following catalogs:- Physics Modules for Students of Education
Further Information
Courses are together with exams the building blocks for modules. Please keep in mind that information on the contents, learning outcomes and, especially examination conditions are given on the module level only – see section "Assignment to Modules" above.
| additional remarks | You will perform a low temperature experiment at liquid helium temperature (4.2 K) to investigate a superconducting tunnel junction - a so-called Josephson junction - consisting of two Nb 100 nm thick electrodes separated by a thin aluminium oxide (AlOx) layer (about 17 nm thick). The junction area is a square with an edge length L of about 20 μm. Josephson junction feature a finite supercurrent (Josephson current) through the tunneling barrier at zero voltage drop between the two junction electrodes. You will measure the maximum Josephson current I_c by recording the IV-characteristics of the junction. The zero-voltage Josephson current across a Josephson junction is proportional to the sine of the phase difference varphi of the macroscopic wave functions describing the two superconducting junction electrodes: I_s = I_c sin(varphi). This phase difference is modified by a magnetic field applied parallel to the tunneling barrier. This results in a characteristic magnetic field dependence of the maximum Josephson current, corresponding to the diffraction pattern of a slit in optics. You will record this pattern and derive the Josephson penetration depth from the period of the pattern. From the experiment you will get basic insights into the phasics of Josephson junctions and in techniques used to perform low temperature experiments. |
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| Links |
Course documents Current information TUMonline entry |