MIT

Researchers observe fractional quantum anomalous Hall effect in multilayer graphene

Researchers at MIT and Japan's National Institute for Materials Science (NIMS) have observed an exotic electronic state in a material made of five layers of graphene, that could enable new forms of quantum computing. 

Generally speaking, the electron is the basic unit of electricity, as it carries a single negative charge. At least, that's the case in most materials in nature. But in very special states of matter, electrons can splinter into fractions of their whole. This phenomenon, known as “fractional charge,” is extremely rare, and if it can be corralled and controlled, the exotic electronic state could help to build resilient, fault-tolerant quantum computers. To date, this effect, known to physicists as the “fractional quantum Hall effect,” has been observed a handful of times, and mostly under very high, carefully maintained magnetic fields. Now, the scientists have also seen the effect in a material that did not require such powerful magnetic manipulation. They found that when five sheets of graphene are stacked like steps on a staircase, the resulting structure inherently provides just the right conditions for electrons to pass through as fractions of their total charge, with no need for any external magnetic field.

Read the full story Posted: Feb 22,2024

Researchers use graphene and boron nitride to develop new brain-like transistor that mimics human intelligence

Researchers at Northwestern University, MIT, Harvard University, CIFAR Azrieli Global Scholars Program and Japan's National Institute for Materials Science have developed a graphene-based synaptic transistor capable of higher-level thinking.

The device simultaneously processes and stores information just like the human brain. In new experiments, the researchers demonstrated that the transistor goes beyond simple machine-learning tasks to categorize data and is capable of performing associative learning.

Read the full story Posted: Dec 25,2023

Researchers discover rare multiferroic behavior in five-layer graphene

Researchers at MIT, Harvard and Japan's National Institute for Materials Science have reported a surprising property in graphene: When stacked in five layers, in a rhombohedral pattern, graphene displays a rare, “multiferroic” state, in which the material exhibits both unconventional magnetism and an exotic type of electronic behavior, which the team has named "ferro-valleytricity".

“Graphene is a fascinating material,” said Long Ju, assistant professor of physics at MIT. “Every layer you add gives you essentially a new material. And now this is the first time we see ferro-valleytricity, and unconventional magnetism, in five layers of graphene. But we don’t see this property in one, two, three, or four layers”. The discovery could promote ultra-low-power, high-capacity data storage devices for classical and quantum computers.

Read the full story Posted: Oct 19,2023

Researchers use graphene transistors to design novel biomimetic sensing system

Researchers from Shanghai Jiao Tong University, Chinese Academy of Fishery Sciences,  BOKU-University of Natural Resources and Life Sciences, University of Oslo and Oslo University Hospital, MIT, 2bind and Avalon GloboCare have designed a novel sensor that could detect the same molecules that naturally occurring cell receptors can identify.

The researchers created a prototype sensor that can detect an immune molecule called CXCL12, down to tens or hundreds of parts per billion. This is an important first step towards developing a system that could be used to perform routine screens for hard-to-diagnose cancers or metastatic tumors, or as a highly biomimetic electronic “nose,” the researchers say.

Read the full story Posted: Jul 28,2023

Graphene used to grow the world's smallest microLEDs and highest-density microLED arrays

Researchers from MIT, in collaboration with researchers from other Universities in the US and Korea, have used graphene (and hBN) to develop full-color vertically-stacked microLEDs  - that achieve the highest array density (5100 PPI) and the smallest size (4 µm) reported to date.

The researchers developed a 2D-materials based layer transfer (2DLT) technique - that involves growing the LEDs on 2D material-coated substrates, removing the LEDs, and then sttacking them. For the red LEDs, the researchers used graphene, coated on a GaAs wafer, while for the green and blue LEDs, they used hBN on sapphire wafers. The graphene red LEDs were transferred using remote epitaxy, while the hBN blue and green ones were removed using Van der Waals epitaxy.

Read the full story Posted: Feb 02,2023

Researchers find superconductivity that can be turned on and off in "magic angle" graphene

Researchers at MIT and National Institute for Materials Science in Tsukuba, Japan, have found a new and intriguing property of “magic-angle” graphene: superconductivity that can be turned on and off with an electric pulse, much like a light switch.

The discovery could lead to ultrafast, energy-efficient superconducting transistors for neuromorphic devices — electronics designed to operate in a way similar to the rapid on/off firing of neurons in the human brain.

Read the full story Posted: Jan 29,2023

Various graphene technologies to be tested during moon and space missions

Graphene Flagship Partners University of Cambridge (UK) and Université Libre de Bruxelles (ULB, Belgium) collaborated with the Mohammed bin Rashid Space Centre (MBRSC, United Arab Emirates) and the European Space Agency (ESA) to test graphene on the Moon. This joint effort sees the involvement of many international partners, such as Airbus Defense and Space, Khalifa University, Massachusetts Institute of Technology, Technische Universität Dortmund, University of Oslo, and Tohoku University.

The MASER15 launch. Credit: John-Charles Dupin/Eurekalert

The Rashid rover is planned to be launched today (30 November 2022) from Cape Canaveral in Florida and will land on a geologically rich and, as yet, only remotely explored area on the Moon’s nearside – the side that always faces the Earth. During one lunar day, equivalent to approximately 14 days on Earth, Rashid will move on the lunar surface investigating interesting geological features.

Read the full story Posted: Nov 30,2022

Researchers design non-volatile switches that manipulate light using phase-change materials and graphene heaters

A team of researchers from Stanford University, University of Washington, The Charles Stark Draper Laboratory, University of Maryland and MIT have reported the design of an energy-efficient, silicon-based non-volatile switch that manipulates light through the use of a phase-change material and graphene heater.

Data centers are dedicated spaces for storing, processing and disseminating data, that enable various applications, from cloud computing to video streaming. In the process, they consume a large amount of energy; As the need for data use grows, so does the need to make data centers more energy-efficient.

Read the full story Posted: Jul 09,2022

PolyJoule unveils graphene-enhanced polymer batteries

PolyJoule, a spin-off of the Massachusetts Institute of Technology (MIT), recently unveiled a new battery technology based on its own proprietary conductive polymers and other organic, non-metallic materials.

MIT backed start-up develops polymer-based batteries image

The battery cells were reportedly tested to perform for 12,000 cycles at 100% depth of discharge. The device is based on a standard, two-electrode electrochemical cell containing the conductive polymers, a carbon-graphene hybrid, and a non-flammable liquid electrolyte. Alternating anodes and cathodes are interwoven and then connected in parallel to form a cell.

Read the full story Posted: Apr 25,2022

Researchers detect evidence of strong electron correlation in a trilayer graphene/hBN moiré superlattice

Researchers from MIT, Harvard University, University of California at Berkeley, Lawrence Berkeley National Laboratory, China's Shanghai Jiao Tong and Fudan Universities and Japan's National Institute for Materials Science have taken a significant step toward understanding electron correlations.

In their new study, the researchers revealed direct evidence of electron correlations in a two-dimensional material called ABC trilayer graphene. This material has previously been shown to switch from a metal to an insulator to a superconductor.

 

Read the full story Posted: Mar 22,2022