Spontaneous breaking of time-reversal symmetry in strongly interacting two-dimensional electron layers in silicon and germanium.
Phys Rev Lett
; 112(23): 236602, 2014 Jun 13.
Article
in En
| MEDLINE
| ID: mdl-24972220
ABSTRACT
We report experimental evidence of a remarkable spontaneous time-reversal symmetry breaking in two-dimensional electron systems formed by atomically confined doping of phosphorus (P) atoms inside bulk crystalline silicon (Si) and germanium (Ge). Weak localization corrections to the conductivity and the universal conductance fluctuations were both found to decrease rapidly with decreasing doping in the SiP and GeP delta layers, suggesting an effect driven by Coulomb interactions. In-plane magnetotransport measurements indicate the presence of intrinsic local spin fluctuations at low doping, providing a microscopic mechanism for spontaneous lifting of the time-reversal symmetry. Our experiments suggest the emergence of a new many-body quantum state when two-dimensional electrons are confined to narrow half-filled impurity bands.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Silicon
/
Electrons
/
Germanium
/
Models, Chemical
Language:
En
Journal:
Phys Rev Lett
Year:
2014
Document type:
Article