Extreme sensitivity of the spin-splitting and 0.7 anomaly to confining potential in one-dimensional nanoelectronic devices

Abstract

Quantum point contacts (QPCs) have shown promise as nanoscale spin-selective components for spintronic applications and are of fundamental interest in the study of electron many-body effects such as the 0.7 x 2e^2/h anomaly. We report on the dependence of the 1D Lande g-factor g* and 0.7 anomaly on electron density and confinement in QPCs with two different top-gate architectures. We obtain g* values up to 2.8 for the lowest 1D subband, significantly exceeding previous in-plane g-factor values in AlGaAs/GaAs QPCs, and approaching that in InGaAs/InP QPCs. We show that g* is highly sensitive to confinement potential, particularly for the lowest 1D subband. This suggests careful management of the QPC's confinement potential may enable the high g* desirable for spintronic applications without resorting to narrow-gap materials such as InAs or InSb. The 0.7 anomaly and zero-bias peak are also highly sensitive to confining potential, explaining the conflicting density dependencies of the 0.7 anomaly in the literature.

arXiv comment23 pages, 7 figures

References in corpus (34)

• Spins in few-electron quantum dots
• Kondo Physics in a Single Electron Transistor
• Possible Spin Polarization in a One-Dimensional Electron Gas
• The Low-Temperature Fate of the 0.7 Structure in a Point Contact: A Kondo-like Correlated State in an Open System
• Spin-charge separation and localization in one-dimension
• Interaction Effects in a One-Dimensional Constriction
• Kondo model for the "0.7 anomaly" in transport through a quantum point contact
• Bias and temperature dependence of the 0.7 conductance anomaly in Quantum Point Contacts
• All-Electric Quantum Point Contact Spin Valve
• Density dependent spin polarisation in ultra low-disorder quantum wires
• Magnetic impurity formation in quantum point contacts
• Many-body spin related phenomena in ultra-low-disorder quantum wires
• Spin separation in cyclotron motion
• Local moment formation in quantum point contacts
• Detecting Spin-Polarized Currents in Ballistic Nanostructures
• What lurks below the last plateau: Experimental studies of the 0.7 x 2e^2/h conductance anomaly in one-dimensional systems
• Spin Properties of Low Density One-Dimensional Wires
• Phenomenological model for the 0.7 conductance feature in quantum wires
• Ballistic Spin Resonance
• Electrical generation of pure spin currents in a two-dimensional electron gas
• Transport Properties of Clean Quantum Point Contacts
• Spin-Incoherent Transport in Quantum Wires
• Probing the microscopic structure of bound states in quantum point contacts
• On the Zero-Bias Anomaly in Quantum Wires
• Non-Kondo zero-bias anomaly in quantum wires
• Observation of the Kondo Effect in a Spin-3/2 Hole Quantum Dot
• The influence of device geometry on many-body effects in quantum point contacts: Signatures of the 0.7 anomaly, exchange and Kondo
• Enhanced Zeeman splitting in Ga0.25In0.75As quantum point contacts
• Evidence for localization and 0.7 anomaly in hole quantum point contacts
• Detector Backaction on the Self-Consistent Bound State in Quantum Point Contacts
• Piezoelectric rotator for studying quantum effects in semiconductor nanostructures at high magnetic fields and low temperatures
• Evidence for the Formation of Quasi-Bound-State in an Asymmetrical Quantum Point Contact
• Spin-dependent transport in a clean one-dimensional channel
• Split-gate quantum point contacts with tunable channel length

Cited by in corpus (13)

• Odd and even Kondo effects from emergent localisation in quantum point contacts
• Statistical study of conductance properties in one-dimensional quantum wires focussing on the 0.7 anomaly
• Mechanisms for strong anisotropy of in-plane g-factors in hole based quantum point contacts
• Dependence of the 0.7 anomaly on the curvature of the potential barrier in quantum wires
• The effect of split gate size on the electrostatic potential and 0.7 anomaly within one-dimensional quantum wires on a modulation doped GaAs/AlGaAs heterostructure
• Scanning Gate Imaging of quantum point contacts and the origin of the 0.7 Anomaly
• Electrostatic potential shape of gate defined quantum point contacts
• Probing strain modulation in a gate-defined one dimensional electron system
• Enhancement mechanism of the electron g-factor in quantum point contacts
• Dynamic nuclear polarization at high Landau levels in a quantum point contact
• Demonstration of electron focusing using electronic lenses in low-dimensional system
• A quantum phase transition detected through one dimensional ballistic conductance
• A one-dimensional spin-orbit interferometer