Projects

Last Thursday the students got the projects that they will work on during the fall term. The following projects were chosen (I include also here the guidelines and references that I gave to them):

i) Thermoelectric devices and measuring techniques – Sec. 2.8 + references 
- Figure out: Mott law, figure of merit, efficiency, Onsager relations, tunneling thermopower of a gapped system, 3-omega method
– Suggested references:http://www.nature.com/nature/journal/v413/n6856/abs/413597a0.html,
http://arxiv.org/abs/1109.1009http://www.sciencemag.org/content/321/5895/1457

ii) Quantum Hall effect, Landau levels and electron optics (pair project) 
– Explain (integer) QHE and Landau levels; explain how QPCs can be used as beam splitters, and how one can do interference experiments with electron wave packets; what is the relation of scattering theory to all this?
– Electron optics: http://www.nature.com/nature/journal/v422/n6930/full/nature01503.htmlhttp://www.sciencemag.org/content/339/6123/1054.full

iii) Primary thermometry with shot noise and Coulomb blockade – Sec. 6.2, 7.6.1 + references 
– Explain the difference between primary and secondary thermometry, describe the challenges
– Mostly references cited in the book

iv) Spin qubits – Sec. 8.5.4 + references 
– Explain the qubit states, their read-out and manipulation, and explore the recent results
– http://www.sciencemag.org/content/309/5744/2180http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.026801http://www.nature.com/nnano/journal/v9/n9/full/nnano.2014.153.htmlhttp://www.sciencemag.org/content/339/6124/1174.abstract
v) Superconducting qubits (pair project or alone one realization) – Sec. 9.4.3 + references 
– Take one realization and explain the qubit states, their read-out and manipulation, possible practical problems and recent results
- Phase/flux/charge qubit references from the book; transmon (or Xmon) qubits: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.111.080502http://www.sciencemag.org/content/339/6124/1169.full.pdfhttp://journals.aps.org/prl/abstract/10.1103/PhysRevLett.107.240501

vi) Rashba and Dresselhaus spin-orbit interaction (part of the pair project) – references 

vii) Topological insulators, quantum spin Hall effect  (part of the pair project) – references 
– Explain 2D and 3D TIs, topological charges (Chern numbers) and bulk-surface correspondence, chirality of the edge/surface states, quantized conductance in 2D TIs, quantum spin Hall effect
– References: http://www.sciencemag.org/content/318/5851/766.abstracthttp://www.nature.com/nature/journal/v452/n7190/full/nature06843.html

viii) Nanoelectromechanical mass/force detection – beginning of Ch. 11 + references 
- Explain some basics of elastic theory regarding the resonances
– Explain the detection scheme, what determines the accuracy?
http://www.nature.com/nnano/journal/v7/n5/full/nnano.2012.42.html + references in the book (bottom of p. 203), http://www.nature.com/nnano/journal/v7/n5/full/nnano.2012.66.html

ix) Qubits and mechanical resonators – Sec. 11.4 + references 
- Explain the idea of “macroscopic quantum mechanics”, and show how this could be studied with mechanical resonators; explain the scheme of measuring superpositions in vibration states
- References: http://www.nature.com/nature/journal/v464/n7289/abs/nature08967.htmlhttp://www.nature.com/nature/journal/v494/n7436/full/nature11821.htmlhttp://www.nature.com/nphys/journal/v8/n5/abs/nphys2262.html

Two people took superconducting qubits. They will each focus on a different specific realization. It is a pity nobody chose spin torque – I would have liked to learn a bit more about it :-) Indeed, my motivation is to learn about the latest developments related to these topics via the student projects, although of course the primary goal is that the students get some kind of an idea about the different systems studied in the field. I haven’t done this before related to this course, so let’s see how it goes. In fact, I did something very similar when I was tutoring a course in quantum computing, I think the year was 2001. The lecturer of the course was Mikio Nakahara, but I was probably more aware of the different realizations. Via the students’ projects we compiled a booklet introducing the different suggested realizations of quantum computing. As far as I understand, part of this work then influenced later Mikio’s book on quantum computing – half of it is on the physical realizations.