Quantum Anomalous Hall Effect

MIT physicists and colleagues created a five-lane superhighway for electrons that could allow ultra-efficient electronics and more.

New technique could lead to clearer tests of whether this fundamental constant is truly constant

With a little twist and the turn of a voltage knob, Cornell researchers have shown that a single material system can toggle between two of the wildest states in condensed matter physics: The quantum anomalous Hall insulator and the two-dimensional topological insulator.

It started as routine research—and ended with a revelation.

Cornell researchers used magnetic imaging to obtain the first direct visualization of how electrons flow in quantum anomalous Hall insulators, and by doing so they discovered the transport current moves through the interior of the material.

MIT physicists report the discovery of electrons forming crystalline structures in a material billionths of a meter thick. The material, rhombohedral pentalayer graphene, joins a family of materials with exotic properties that may have other "relatives."

MIT's Long Ju uncovered anomalous fractional charge in graphene, a material previously not expected to exhibit such behavior, focusing on pentalayer graphene, consisting of five slightly staggered sheets arranged like a staircase.

A new review paper on magnetic topological materials introduces the new theoretical concept that interweave magnetism and topology.

MIT physicists have taken a key step toward solving the puzzle of what leads electrons to split into fractions of themselves. Their solution sheds light on the conditions that give rise to exotic electronic states in graphene and other two-dimensional systems.

A University of Washington-led team has made a key quantum computing breakthrough by detecting fractional quantum anomalous Hall states in semiconductor material flakes, which could be instrumental in creating stable, fault-tolerant qubits. Quantum computing could revolutionize our world. For spe

Quantum computing could revolutionize our world. For specific and crucial tasks, it promises to be exponentially faster than the zero-or-one binary technology that underlies today's machines, from supercomputers in laboratories to smartphones in our pockets. But developing quantum computers hinges on building a stable network of qubits—or quantum bits—to store information, access it and perform computations.

RIKEN physicists have created an exotic quantum state in a device with a disk-like geometry for the first time, showing that edges are not required. This demonstration opens the way for realizing other novel electronic behavior. Their findings are published in Nature Physics.

A new review paper on magnetic topological materials introduces a theoretical concept that interweaves magnetism and topology. It identifies and surveys potential new magnetic topological materials and suggests possible future applications in spin and quantum electronics and as materials for efficient energy conversion.

MIT physicists have observed fractional quantum Hall effect in simple pentalayer graphene. The finding could make it easier to develop more robust quantum computers.

Cornell researchers have used magnetic imaging to obtain the first direct visualization of how electrons flow in a special type of insulator, and by doing so they discovered that the transport current moves through the interior of the material, rather than at the edges, as scientists had long assumed.

Researchers at the Weizmann Institute of Science, the Barcelona Institute of Science and Technology and the National Institute for Material Science in Tsukuba (Japan) have recently probed a Chern mosaic topology and Berry-curvature magnetism in magic-angle graphene. Their paper, published in Nature Physics, offers new insight about topological disorder that can occur in condensed matter physical systems.

Recently, Associate Professor Yong-Chun Liu of the Department of Physics and others have found the hybrid skin-topological effect induced by gain and loss and the parity-time phase transition between skin-topological modes. The research results were published in Physical Review Letters under the title of "Gain-loss-induced hybrid skin-topological effect."

The kagome pattern, a network of corner-sharing triangles, is well known amongst traditional Japanese basket weavers—and condensed matter physicists. The unusual geometry of metal atoms in the kagome lattice and resulting electron behavior makes it a playground for probing weird and wonderful quantum phenomena that form the basis of next-generation device research.