Home > Press > Spin current on topological insulator detected electrically at room temperature
This image shows the schematics of the spin current on a topological insulator surface, with the spin direction (S) perpendicular to the current direction (kx). The zoom in schematic shows the electronic band structure on the surface of the topological insulator. The spin polarization on topological insulator surface is electrically probed by a ferromagnetic tunnel contact (FM). CREDIT: André Dankert |
Abstract:
Researchers at Chalmers University of Technology have for the first time reported the electrical detection of spin current on topological insulator surfaces at room temperature by employing a ferromagnetic detector. The findings have been published in the journal Nano Letters.
Solid-state materials were conventionally divided into three different classes such as conductors, semiconductors and insulators. Recently, a new class of materials has been proposed and realized, called "topological insulators", where both the insulating and conducting properties can co-exist in the same material.
Topological insulators are insulators inside the bulk, but are conducting on their surfaces with less resistance than the conventional materials. This is possible due to their uniquely strong interaction between electrons' spin and orbital angular momentum with their time reversal symmetry. The interaction is so strong that the spin angular momentum of the electrons is locked perpendicular to their momentum, and generates a spontaneous spin polarized current on the surfaces of topological insulators by applying an electric field.
These spin polarized conducting electrons on the surface have no mass and are extremely robust against most perturbations from defects or impurities, and can enable the propagation of dissipationless spin currents.
The researchers from Chalmers detected the surface spin current electrically on a topological insulator called bismuth selenide (Bi2Se3) for the first time at room temperature employing ferromagnetic tunnel contacts. Such contacts are known to be very sensitive to spin polarization and probe the Bi2Se3 surface by measuring the magnetoresistance due to parallel and anti-parallel alignment of the spin current and the ferromagnet magnetization direction.
"The key factors for these room temperature results are good quality topological insulator crystals and spin sensitive ferromagnetic tunnel contacts carefully prepared by clean room nanofabrication", explains Dr. André Dankert, the lead author of the paper.
Earlier reports in this research field were limited only to measurements at cryogenic temperatures. From the results on the magnitude of the spin signal, its sign, and control experiments, using different measurement configurations, angles and interface conditions, the author's rule out other known physical effects.
"Our results show the electrical accessibility of spin currents on topological insulator surfaces up to room temperature and pave the way for further developments, which can be useful for spin based information processing in the future", says associate professor Saroj Dash, who leads the research group.
However, Saroj Dash cautions that the research on development of these new class materials and measurement techniques are still in its early stage and more experiments are required for further understanding.
####
For more information, please click here
Contacts:
Johanna Wilde
46-317-722-029
Copyright © Chalmers University of Technology
If you have a comment, please Contact us.Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Related Links |
Related News Press |
News and information
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Possible Futures
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Spintronics
Quantum materials: Electron spin measured for the first time June 9th, 2023
Linearly assembled Ag-Cu nanoclusters: Spin transfer and distance-dependent spin coupling November 4th, 2022
Chip Technology
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Utilizing palladium for addressing contact issues of buried oxide thin film transistors April 5th, 2024
HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024
Quantum Computing
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
Discoveries
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
New micromaterial releases nanoparticles that selectively destroy cancer cells April 5th, 2024
Utilizing palladium for addressing contact issues of buried oxide thin film transistors April 5th, 2024
Materials/Metamaterials/Magnetoresistance
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Focused ion beam technology: A single tool for a wide range of applications January 12th, 2024
Announcements
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
The latest news from around the world, FREE | ||
Premium Products | ||
Only the news you want to read!
Learn More |
||
Full-service, expert consulting
Learn More |
||