Wigner molecules in phosphorene quantum dots

Abstract

We study Wigner crystallization of electron systems in phosphorene quantum dots with confinement of an electrostatic origin with both circular and elongated geometry. The anisotropy of the effective mass allows for the formation of Wigner molecules in the laboratory frame with a confined charge density that has lower symmetry than the confinement potential. We find that in circular quantum dots separate single-electron islands are formed for two and four confined electrons but not for three trapped carriers. The spectral signatures of the Wigner crystallization to be resolved by transport spectroscopy are discussed. Systems with Wigner molecule states are characterized by a nearly degenerate ground state at $B=0$ and are easily spin-polarized by the external magnetic field. In electron systems for which the single-electron islands are not formed, a more even distribution of excited states at $B=0$ is observed, and the confined system undergoes ground state symmetry transitions at magnetic fields of the order of 1 Tesla. The system of five electrons in a circular quantum dot is indicated as a special case with two charge configurations that appear in the ground-state as the magnetic field is changed: one with the single electron islands formed in the laboratory frame and the other where only the pair-correlation function in the inner coordinates of the system has a molecular form as for three electrons. The formation of Wigner molecules of quasi-1D form is easier for the orientation of elongated quantum dots along the zigzag direction with heavier electron mass. The smaller electron effective mass along the armchair direction allows for freezing out the transverse degree of freedom in the electron motion.

References in corpus (48)

• Black phosphorus field-effect transistors
• Phosphorene: A New 2D Material with High Carrier Mobility
• High-mobility transport anisotropy and linear dichroism in few-layer black phosphorus
• Spins in few-electron quantum dots
• Quasiparticle band structure and tight-binding model for single- and bilayer black phosphorus
• Energy spectra of quantum rings
• Quantum Hall Effect in Black Phosphorus Two-dimensional Electron Gas
• Wigner Crystallization in mesoscopic 2D electron systems
• Quantum Hall Effect in Ultrahigh Mobility Two-dimensional Hole Gas of Black Phosphorus
• Crossover from Fermi liquid to Wigner molecule behavior in quantum dots
• Gate Tunable Quantum Oscillations in Air-Stable and High Mobility Few-Layer Phosphorene Heterostructures
• Observation of Wigner crystal of electrons in a monolayer semiconductor
• Symmetry breaking and quantum correlations in finite systems: Studies of quantum dots and ultracold Bose gases and related nuclear and chemical methods
• Toward a realistic description of multilayer black phosphorus: from $GW$ approximation to large-scale tight-binding simulations
• Spin interactions and switching in vertically tunnel-coupled quantum dots
• On the formation of Wigner molecules in small quantum dots
• Imaging the Wigner Crystal of Electrons in One Dimension
• Observation and Spectroscopy of a Two-Electron Wigner Molecule in an Ultra-Clean Carbon Nanotube
• Excitation spectrum of two correlated electrons in a lateral quantum dot with negligible Zeeman splitting
• Wigner Molecules in Nanostructures
• Spin-based quantum computation in multielectron quantum dots
• A molecular state of correlated electrons in a quantum dot
• Electronic Structure and the Properties of Phosphorene Systems
• Electro-optical properties of phosphorene quantum dots
• Integer and Fractional Quantum Hall effect in Ultra-high Quality Few-layer Black Phosphorus Transistors
• Quantum Hall Effect in Electron-Doped Black Phosphorus Field-Effect Transistors
• Spatial ordering of charge and spin in quasi one-dimensional Wigner molecules
• Crystallization in the Fractional Quantum Hall Regime Induced by Landau-level Mixing
• Gauge invariant grid discretization of Schrödinger equation
• $k\cdot p$ theory for phosphorene: Effective g-factors, Landau levels, and excitons
• Coherent control and spectroscopy of a semiconductor quantum dot Wigner molecule
• Electronic properties of bilayer phosphorene quantum dots in the presence of perpendicular electric and magnetic fields
• Three-electron anisotropic quantum dots in variable magnetic fields: exact results for excitation spectra, spin structures, and entanglement
• Wigner molecules in carbon-nanotube quantum dots
• Quantum Transport in Ambipolar Few-layer Black Phosphorus
• Double-well ultracold-fermions computational microscopy: Wave-function anatomy of attractive-pairing and Wigner-molecule entanglement and natural orbitals
• Two-body Wigner molecularization in asymmetric quantum dot spin qubits
• Ultracold few fermionic atoms in needle-shaped double wells: spin chains and resonating spin clusters from microscopic Hamiltonians emulated via antiferromagnetic Heisenberg and t-J models
• One-dimensional few-electron effective Wigner crystal in quantum and classical regimes
• Ground-state of two-dimensional finite electron systems in the Quantum Hall regime
• Molecular formations and spectra due to electron correlations in three-electron hybrid double-well qubits
• Real Space Hartree-Fock Configuration Interaction Method For Complex Lateral Quantum Dot Molecules
• Natural orbitals for the ab initio no-core configuration interaction approach
• Electrostatic quantum dot confinement in phosphorene
• Fermionic versus bosonic behavior of confined Wigner molecules
• Effects of interedge scattering on the Wigner crystallization in graphene nanoribbons
• Annular confinement for electrons on liquid helium
• Coupled cluster theory for the ground and excited states of two dimensional quantum dots