טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentPariente Udi
SubjectChemical Potential Measurement of a Two Dimensional
Electron Gas with AC Modulation of the Magnetic
Field
DepartmentDepartment of Physics
Supervisor Professor Michael Reznikov
Full Thesis textFull thesis text - English Version


Abstract

In this work we report the measurements of the magnetic field induced recharging of the gated two dimensional electron gas (2DEG) with the aim of extracting the chemical potential derivative with respect to the magnetic field, dm/dB. We focused on the normal to the two dimensional plane magnetic field, especially on the Quantum Hall effect regime.


In the first chapter we review the different experimental techniques, which allow measuring of the chemical potential derivatives and related quantities. We then introduce the magnetic field induced recharging technique, and compare it to the others.


In the second chapter we describe the experimental setup in some detail. We discuss the peculiar problems which arise from the necessity to modulate magnetic field while maintaining low sample temperature and avoiding direct magnetic induction.


We also describe a little bit detached from the main line technological effort of improving contacts in Si transistors, leaving technicalities to the Appendix.


We then present the experimental results and compare them with theory. We point to a problem in measurements which arises in the minima of the diagonal conductivity of the 2DEG, and discuss it in detail in the next chapter. We finally conclude on the region of applicability of the magnetic field induced recharging method.