Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Exotic material keeps frustrated electrons flipping

RIKEN scientists have discovered a new state of matter with unusual magnetic properties—its constituent electrons are in a continuous state of flux, even at incredibly cold temperatures.

Magnetic, temperature and structural studies have yielded new insights on the material sodium iridium oxide

RIKEN scientists have discovered a new state of matter with unusual magnetic properties—its constituent electrons are in a continuous state of flux, even at incredibly cold temperatures.

As electrons spin, they generate a magnetic field which can point ‘up’ or ‘down’. Within solid materials, an electron will generally try to adopt the opposite spin orientation to its neighbor, just as two bar magnets will flip around so that north and south poles line up next to each other.

In more common lattice structures, where atoms stack up like oranges on a greengrocers stall, it’s easy for electrons to achieve this ordered arrangement. But in certain materials, the arrangement of atoms can make it impossible for the electrons to line up with all of their neighbors, and they are said to be ‘frustrated’.

One example of a frustrated material contains a network of atoms arranged into corner-sharing triangles. This is called a kagome structure after a type of Japanese basket that has the same pattern (Fig. 1).

The electrons’ response to this frustration is to constantly flip their magnetic fields to reduce the repulsion between them. In this ‘quantum spin-liquid state’, the quantum effect is expected to stop flipping electrons from freezing out into a static arrangement even at absolute zero (-273.15 ˚C—the coldest temperature possible). Several materials have been claimed to contain possible quantum spin-liquid states, but none have been confirmed.

Hidenori Takagi and Yoshihiko Okamoto of RIKEN’s Discovery Research Institute, Wako, and colleagues, have now found that sodium iridium oxide (Na4Ir3O8) exhibits quantum spin-liquid behavior, even when cooled to -271 ˚C. This was confirmed by magnetic, temperature and structural studies, involving both neutron and x-ray diffraction.

The material contains a network of iridium atoms that form a three-dimensional pattern of corner-shared triangles—dubbed a hyperkagome lattice (Fig. 2), which can be viewed as a slightly twisted—but different structure—to the kagome structure, explains Takagi. Theoretical calculations are consistent with this type of structure showing spin-liquid behavior.

“We believe it is the strongest candidate [for a quantum spin liquid],” says Takagi.

The scientists say that the material is “a fascinating playground for quantum magnetism”, and now hope to study the spin-liquid state further. This should to help build up a detailed description of the phenomenon using quantum theory, describing on a subatomic level exactly how the spinning electrons interact with each other.

1. Okamoto, Y., Nohara, M., Aruga-Katori, H. & Takagi, H. Spin-liquid state in the S = 1/2 hyperkagome antiferromagnet Na4Ir3O8. Physical Review Letters 99, 137207 (2007).

Saeko Okada | ResearchSEA
Further information:

More articles from Materials Sciences:

nachricht From ancient fossils to future cars
21.10.2016 | University of California - Riverside

nachricht Study explains strength gap between graphene, carbon fiber
20.10.2016 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>