Repository logo

Weak localization and weak antilocalization in doped germanium epilayers

Change log


Newton, PJ 
Holmes, SN 
Myronov, M 
Barnes, CHW 


The magnetoresistance of 50 nm thick epilayers of doped germanium is measured at a range of temperatures down to 1.6 K. Both n- and p-type devices show quantum corrections to the conductivity in an applied magnetic field, with n-type devices displaying weak localization and p-type devices showing weak antilocalization. From fits to these data using the Hikami-Larkin-Nagaoka model, the phase coherence length of each device is extracted, as well as the spin diffusion length of the p-type device. We obtain phase coherence lengths as large as 325 nm in the highly doped n-type device, presenting possible applications in quantum technologies. The decay of the phase coherence length with temperature is found to obey the same power law of lφ∝Tc, where c=-0.68±0.03, for each device, in spite of the clear differences in the nature of the conduction. In the p-type device, the measured spin diffusion length does not change over the range of temperatures for which weak antilocalization can be observed. The presence of a spin-orbit interaction manifested as weak antilocalization in the p-type epilayer suggests that these structures could be developed for use in spintronic devices such as the spin-FET, where significant spin lifetimes would be important for efficient device operation.



5108 Quantum Physics, 51 Physical Sciences, 5104 Condensed Matter Physics

Journal Title

Applied Physics Letters

Conference Name

Journal ISSN


Volume Title



American Institute of Physics
Engineering and Physical Sciences Research Council (EP/J003638/1)
This work was supported by the EPSRC funded “Spintronic device physics in Si/Ge heterostructures” EP/J003263/1 and EP/J003638/1 projects and a Platform Grant No. EP/J001074/1.
Is supplemented by: