Related Experiment Video
Updated: Jun 14, 2026
11:33
All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
Spin filtering by field-dependent resonant tunneling.
Zoran Ristivojevic1, George I Japaridze, Thomas Nattermann
1Institut für Theoretische Physik, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany.
Physical Review Letters
|April 7, 2010
Summary
Spin-polarized current in quantum wires is achievable with specific impurity configurations and tunable parameters. Complete spin polarization is possible at low temperatures if electron interactions are not excessively repulsive.
Area of Science:
- Condensed matter physics
- Quantum transport phenomena
Background:
- Quantum wires are fundamental systems for studying electron transport.
- Interactions and impurities significantly influence quantum transport properties.
- External magnetic fields can control spin-dependent phenomena.
Purpose of the Study:
- To theoretically investigate spin-polarized transport in a spinful, interacting quantum wire.
- To analyze the effect of two pointlike impurities on current.
- To identify conditions for achieving tunable spin polarization.
Main Methods:
- Theoretical modeling of electron transport.
- Analysis of a one-channel interacting quantum wire model.
- Consideration of an external magnetic field and two impurities.
- Examination under small voltage bias.
Main Results:
- Spin-polarized current emerges at specific, tunable points in the parameter space.
- Complete spin polarization is attainable under certain conditions.
- Repulsive electron-electron interaction strength is a critical factor.
Conclusions:
- The study demonstrates tunability of spin-polarized current in interacting quantum wires.
- Low temperatures and moderate repulsive interactions are key for achieving full spin polarization.
- External magnetic fields and impurity configurations offer control over spin transport.
Related Concept Videos
01:23Parallel Resonance
The parallel RLC circuit is an arrangement where the resistor (R), inductor (L), and capacitor (C) are all connected to the same nodes and, as a result, share the same voltage across them. The parallel RLC circuit is analyzed in terms of admittance (Y), which reflects the ease with which current can flow. The admittance is given by:
01:12Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
01:14Sound Waves: Resonance
Resonance is produced depending on the boundary conditions imposed on a wave. Resonance can be produced in a string under tension with symmetrical boundary conditions (i.e., has a node at each end). A node is defined as a fixed point where the string does not move. The symmetrical boundary conditions result in some frequencies resonating and producing standing waves, while other frequencies interfere destructively. Sound waves can resonate in a hollow tube, and the frequencies of the sound...
01:27Passive Filters
Passive filters are utilized to shape the frequency spectrum of signals across a diverse array of applications. These filters, using only passive elements like resistors (R), inductors (L), and capacitors (C), are capable of selectively allowing or blocking certain frequency ranges without the need for external power sources.
Low-Pass Filters
Low-pass filters are designed to transmit signals with frequencies lower than the cutoff frequency, ωc, and attenuate those above it. The cutoff frequency...
Low-Pass Filters
Low-pass filters are designed to transmit signals with frequencies lower than the cutoff frequency, ωc, and attenuate those above it. The cutoff frequency...