Valleytronics News - Page 2

Researchers discover the formation of valley domain, potentially expand valleytronics technology

Researchers from Korea's Daegu Gyeongbuk Institute of Science and Technology (DGIST) discovered the formation of valley domain, which can expand valleytronics technology.

Formation of valley domain in molybden disulphide (DGIST)

The researchers say that they have solved the stability problem inherent in valley spin in valleytronics devices by discovering the formation of valley domain in 2D molybdenum disulfide (MoS2). The team identified that a valley domain formed in an extreme nano structure can be used to store information in place of spin.

Read the full story Posted: Jul 25,2019

EPFL researchers developed a new to manipulate excitons valleys

Researchers from EPFL's Laboratory of Nanoscale Electronics and Structures (LANES) developed a new way to control the valley properties of excitons and change the polarization of the light they generate.

Excitons, or electron and electron hole pairs, are created when an electron absorbs light and moves into a higher energy band. To research the excitons, the researchers used a material made from tungsten diselenide (WSe2) and molybdenum diselenide (MoSe2), and a circular polarized laser that was focused on the film.

Read the full story Posted: Jan 06,2019

Researchers develop a graphene-based topological valley valve

Researchers from Penn State University developed a topological valley valve, which controls electron flow. Using electron "beam splitters", the researchers achieved high-level of electron control.

Using bilayer graphene, the researcher created electron waveguides created by gates defined with extreme precision using state-of-the-art electron beam lithography.By controlling the topology of the waveguides (the valley-momentum locking of the electrons), the researchers can control electron flow.

Read the full story Posted: Dec 12,2018

The US NSF allocates $20-25 million towards material research aimed towards quantum engineering and science

The US National Science Foundation (NSF) has allocated $20-25 million for a new six year program called "Enabling Quantum Leap: Convergent Accelerated Discovery Foundries for Quantum Materials Science, Engineering, and Information" (Q-AMASE-i).

Q-AMASE-i encompasses many clases of materials, includings ones that explore the paradigms or spintronics, hybrid 2D materials - and Valleytronics.

Read the full story Posted: Sep 03,2018

Researchers find that electrons in Bismuth prefer to stay in one specific valley out of the six available ones

Researchers from Princeton University observed that electrons in bismuth prefer to crowd into one valley rather than distributing equally into the six available valleys. This behavior creates a type of electricity called ferroelectricity, which involves the separation of positive and negative charges onto opposite sides of a material.

Elliptical orbits of bismuth surface electrons in a large magnetic field

The finding confirms that ferroelectricity arises naturally on the surface of bismuth when electrons collect in a single valley. This behavior could be exploited in future Valleytronics devices. The existence of six valleys in bismuth raises the possibility of distributing information in six different states.

Read the full story Posted: Aug 19,2018

Researchers use polarized laser to switch valley states in an extremely fast way

Researchers from the University of Michigan, the University of Marburg and the University of Regensburg used circularly polarized infrared laser pulses to move electrons between valleys in a 2D material made of Tungsten and Selenium in a honeycomb lattice (similar to graphene).

These laser pulses are extremely short - just a few femtoseconds long, which results in extremely fast data switching. The researchers say that such "lightwave" computing could be millions of times faster than current computers, and be used to develop quantum computing architectures.

Read the full story Posted: May 10,2018

SnS is found to be a promising valleytronics material

Researchers from Berkeley Lab discovered that Tin(II)-Sulfide (SnS) is a promising valleytronics material as its valleys have different shapes and responses to different polarizations of light. This property means that in SnS it is easy to read valleytronics data bits.

SnS Valleys respond to light polarization (image)

The researchers have shown that SnS is able to absorb different polarizations of light and then selectively re-emit light of different colors at different polarizations. In such a material, it is possible to concurrently access both the usual electronic and valleytronic degrees of freedom.

Read the full story Posted: Apr 15,2018

Researchers confirm the existence of chiral phonons in a 2D material

Researchers from the DoE Lawrence Berkeley National Laboratory have proved the existence of chirac phonons - a shaking motion in the structure of 2D material that possesses a naturally occurring circular rotation. This rotation may mean that the material is promising for data-storage based on valleytronics.

Chiral Phonons in WSe2 (Berkeley Lab)

The researchers used tungsten diselenide (WSe2), a material that has an unusual ability to sustain special electronic properties that are far more fleeting in other materials. With this new discovery of the chirac phonons, the researchers believe that controlling the rotation direction could prove to be a stable mechanism to carry and store information.

Read the full story Posted: Feb 04,2018

Researchers design a complete valleytronic-based logic gate

Researchers from the SUTD-MIT International Design Center at Singapore University of Technology and Design have demonstrated a concrete working design of valleytronic-based logic gate capable of performing all 16 types of boolean logic operators. This logic gate can also perform logically-reversible computing - useful in many applications ranging from cryptography to signal processing and quantum computing.

To achieve this logic gate, the researchers used a 2D-material (Phosphorene) in combination with a topological Weyl/Dirac semi-metal thin films. The valleytronics gate encodes extra bits of information in the valley polarization of the computational output to preserve logical-reversibility.

Read the full story Posted: Dec 21,2017

Researchers find a way to achieve current valley separation in graphene

Researchers from Ohio University have found a simple yet effective way to achieve current valley separation in graphene. The idea is based on inversion symmetry, or the creation of properly oriented obstacles that break an important symmetry of the graphene crystal.

Valley current asymmetry in graphene

This is a theoretical work, but the researchers say that the results could enable seperating and controling valley currents in graphene in real experiments which will hopefully lead to the utilization of graphene in future valleytronics devices.

Read the full story Posted: Nov 19,2017