Spontaneous breaking of time reversal symmetry in strongly interacting two dimensional electron layers in silicon and germanium

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 Si:P and Ge:P $\delta -$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.

References in corpus (5)

• Mott Transition in the Two-Dimensional Hubbard Model
• Coherent back-scattering near the two-dimensional metal-insulator transition
• Electronic transport in two dimensional Si:P $\delta$-doped layers
• Nanoscale ferromagnetism in non-magnetic doped semiconductors
• Suppression of low-frequency noise in two-dimensional electron gas at degenerately doped Si:P δ-layers

Cited by in corpus (6)

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• Influence of magnetic and electric fields on universal conductance fluctuations in thin films of the Dirac semi-metal Cd3As2
• Suppression of mid-infrared plasma resonance due to quantum confinement in delta-doped silicon
• Quantum Transport Reservoir Computing
• Silicon Donor Array as a Disordered One-Dimensional Electron Gas