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 (17)

• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Metallic behavior and related phenomena in two dimensions
• Chiral superconductivity from repulsive interactions in doped graphene
• Metal-Insulator Transition in Disordered Two-Dimensional Electron Systems
• Mott--Hubbard transition vs. Anderson localization of correlated, disordered electrons
• Possibility of High Tc Superconductivity in doped Graphene
• Interaction-induced magnetoresistance: From the diffusive to the ballistic regime
• Conducting phase in the two-dimensional disordered Hubbard model
• Mott Transition in the Two-Dimensional Hubbard Model
• Observation of non-gaussian conductance fluctuations at low temperatures in Si:P(B) at the metal-insulator transition
• Spin-valley phase diagram of the two-dimensional metal-insulator transition
• Universal conductance fluctuations in three dimensional metallic single crystals of Si
• Electronic transport in two dimensional Si:P $\delta$-doped layers
• Coherent back-scattering near the two-dimensional metal-insulator transition
• Nanoscale ferromagnetism in non-magnetic doped semiconductors
• Magnetotransport of CeRhIn5
• Suppression of low-frequency noise in two-dimensional electron gas at degenerately doped Si:P δ-layers

Cited by in corpus (10)

• Theory of one and two donors in Silicon
• Probing the Quantum States of a Single Atom Transistor at Microwave Frequencies
• Bottom-up assembly of metallic germanium
• Spontaneous time reversal symmetry breaking at individual grain boundaries in graphene
• Universal conductance fluctuations and direct observation of crossover of symmetry classes in topological insulators
• Influence of magnetic and electric fields on universal conductance fluctuations in thin films of the Dirac semi-metal Cd3As2
• Anderson Localization of Electrons in Silicon Donor Chains
• 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