Details
| Original language | English |
|---|---|
| Article number | 115409 |
| Journal | Physical Review B |
| Volume | 102 |
| Issue number | 11 |
| Publication status | Published - 9 Sept 2020 |
Abstract
The magnetoconductance of Bi films grown epitaxially on Si(111) for a film thickness between 10 and 100 bilayers (BL) was investigated at a temperature of T=9K in magnetic fields up to 4 T oriented perpendicular to the surface plane. The thickness dependence of magnetoconductance (MC) and Hall resistivity was investigated in order to derive thickness dependent charge carrier concentrations as well as their mobilities and to identify corrections by weak antilocalization (WAL) to magnetoconductance. While the electronic transport in ultrathin films up to 30 bilayers (BL) turned out to take place mainly within the surface states, contributions of (bulk derived) quantum well states mix in at larger thicknesses and dominate incoherent transport above 70 BL. On the contrary, for the WAL contribution at magnetic fields normal to the surface, scattering within the surface states dominates at all thicknesses, as evident from the gradual change from values of α=-0.35 to α=-1 as a function of thickness. This finding reflects the decrease of coupling between the two interfaces going from a single combined conduction channel to two independent channels at the highest film thickness. Quick changes of both parts of magnetoconductance as a function of film thickness at the thinnest films seem to be strain induced by the Bi/Si interface. These results will advance the understanding of the transport properties of Bi thin films and reveal exotic quantum phenomena.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Physical Review B, Vol. 102, No. 11, 115409, 09.09.2020.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Thickness-dependent electronic transport through epitaxial nontrivial Bi quantum films
AU - Abdelbarey, Doaa
AU - Koch, Julian
AU - Mamiyev, Zamin
AU - Tegenkamp, Christoph
AU - Pfnür, Herbert
N1 - Funding information: We would like to thank Dr. Suguru Ito for several fruitful discussions on his photoemission spectroscopy data. This work has been supported by the Deutsche Forschungsgemeinschaft through project Pf238/31.
PY - 2020/9/9
Y1 - 2020/9/9
N2 - The magnetoconductance of Bi films grown epitaxially on Si(111) for a film thickness between 10 and 100 bilayers (BL) was investigated at a temperature of T=9K in magnetic fields up to 4 T oriented perpendicular to the surface plane. The thickness dependence of magnetoconductance (MC) and Hall resistivity was investigated in order to derive thickness dependent charge carrier concentrations as well as their mobilities and to identify corrections by weak antilocalization (WAL) to magnetoconductance. While the electronic transport in ultrathin films up to 30 bilayers (BL) turned out to take place mainly within the surface states, contributions of (bulk derived) quantum well states mix in at larger thicknesses and dominate incoherent transport above 70 BL. On the contrary, for the WAL contribution at magnetic fields normal to the surface, scattering within the surface states dominates at all thicknesses, as evident from the gradual change from values of α=-0.35 to α=-1 as a function of thickness. This finding reflects the decrease of coupling between the two interfaces going from a single combined conduction channel to two independent channels at the highest film thickness. Quick changes of both parts of magnetoconductance as a function of film thickness at the thinnest films seem to be strain induced by the Bi/Si interface. These results will advance the understanding of the transport properties of Bi thin films and reveal exotic quantum phenomena.
AB - The magnetoconductance of Bi films grown epitaxially on Si(111) for a film thickness between 10 and 100 bilayers (BL) was investigated at a temperature of T=9K in magnetic fields up to 4 T oriented perpendicular to the surface plane. The thickness dependence of magnetoconductance (MC) and Hall resistivity was investigated in order to derive thickness dependent charge carrier concentrations as well as their mobilities and to identify corrections by weak antilocalization (WAL) to magnetoconductance. While the electronic transport in ultrathin films up to 30 bilayers (BL) turned out to take place mainly within the surface states, contributions of (bulk derived) quantum well states mix in at larger thicknesses and dominate incoherent transport above 70 BL. On the contrary, for the WAL contribution at magnetic fields normal to the surface, scattering within the surface states dominates at all thicknesses, as evident from the gradual change from values of α=-0.35 to α=-1 as a function of thickness. This finding reflects the decrease of coupling between the two interfaces going from a single combined conduction channel to two independent channels at the highest film thickness. Quick changes of both parts of magnetoconductance as a function of film thickness at the thinnest films seem to be strain induced by the Bi/Si interface. These results will advance the understanding of the transport properties of Bi thin films and reveal exotic quantum phenomena.
UR - http://www.scopus.com/inward/record.url?scp=85092939453&partnerID=8YFLogxK
U2 - 10.1103/physrevb.102.115409
DO - 10.1103/physrevb.102.115409
M3 - Article
VL - 102
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 11
M1 - 115409
ER -