Valley splitting of Si/Si1-xGex heterostructures in tilted magnetic fields.

Journal Article · Sat Dec 31 23:00:00 EST 2005 · Proposed for publication in Physical Review B.

OSTI ID:952152

Pan, Wei; Schaffler, F ^[1]; Muhlberger, M ^[1]; Lyon, S ^[2]; Xie, Ya-Hong ^[3]; Lai, K W ^[2]; Tsuri, D ^[2]; Liu, J ^[3]; Lu, T M ^[2]

---

1. Universitat Linz, Austria
2. Princeton University, Princeton, NJ
3. UCLA, Los Angeles, CA

We have investigated the valley splitting of two-dimensional electrons in high-quality Si/Si{sub 1-x}Ge{sub x} heterostructures under tilted magnetic fields. For all the samples in our study, the valley splitting at filling factor {nu} = 3 ({Delta}{sub 3}) is significantly different before and after the coincidence angle, at which energy levels cross at the Fermi level. On both sides of the coincidence, a linear dependence of {Delta}{sub 3} on the electron density was observed, while the slope of these two configurations differs by more than a factor of 2. We argue that screening of the Coulomb interaction from the low-lying filled levels, which also explains the observed spin-dependent resistivity, is responsible for the large difference of {Delta}{sub 3} before and after the coincidence.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 952152
• Report Number(s): SAND2006-0943J
• Journal Information: Proposed for publication in Physical Review B., Journal Name: Proposed for publication in Physical Review B.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ELECTRON DENSITY
ENERGY LEVELS
FERMI LEVEL
GERMANIUM SILICIDES
MAGNETIC FIELDS
SILICON