Quantum mechanics

Professor Jeff Hoffman delivers a lecture as part of the materials for his MITx course, "Introduction to Aerospace Engineering." MITx courses have seen over 500,000 enrollments since the start of the Covid-19 pandemic.

Learning during lockdown

Whether seeking a career change or rediscovering intellectual pursuits, learners worldwide turn to MITx courses.

June 30, 2020

Diagram depicts the different conditions that give rise to a Kohn anomaly in ordinary metals (at left), versus a material called a Weyl semimetal (at right). The vertical axis shows energy, while the horizontal axis is momentum space. In the conventional metal, a Kohn anomaly can happen when a phonon (q) links two parts of a property called the Fermi surface, which is shown in blue. In the Weyl se...

Newly observed phenomenon could lead to new quantum devices

Exotic states called Kohn anomalies could offer clues to why some materials have the electronic properties they do.

June 12, 2020

MIT Senior Research Scientist Jagadeesh Moodera and his group use a molecular beam epitaxy system to precisely control the fabrication of ultrathin quantum material combination layer structures. Studying the interfaces between such materials could lead to novel interface phenomena and new energy-efficient quantum devices.

Exploring new paths to future quantum electronics

Jagadeesh Moodera and colleagues to investigate interface-driven phenomena in quantum materials in the quest for energy-efficient quantum electronics.

May 11, 2020

MIT physicist and historian David Kaiser explores the complicated history of quantum physics in a new book, “Quantum Legacies: Dispatches from an Uncertain World,” published by the University of Chicago Press.

How growth of the scientific enterprise influenced a century of quantum physics

In a new book, Professor David Kaiser describes dramatic shifts in the history of an evolving discipline.

April 29, 2020

This illustration shows the characteristic “sheriff star”-type pattern of the Fermi surface, or distribution of electron energy and momentum, for the kagome metal FeSn, a 1-to-1 ratio compound of iron and tin.

MIT researchers realize “ideal” kagome metal electronic structure

Newly synthesized compound of iron and tin atoms in 1-to-1 ratio displays unique behavior.

December 12, 2019

MIT chemists have observed, for the first time, inversion of the umbrella-like ammonia molecule by quantum tunneling.

Chemists observe “spooky” quantum tunneling

Extremely large electric fields can prevent umbrella-shaped ammonia molecules from inverting.

November 4, 2019

$The repeating patterns in a snowflake are a classic example of beautiful, geometric fractals. Now MIT scientists have discovered fractal-like patterns in the magnetic configurations of a quantum material for the first time.$

Scientists discover fractal patterns in a quantum material

The X-ray-focusing lens used in the experiment is based on a design used in lighthouses for centuries.

October 16, 2019

Scanning Transmission Electron Microscope image (STEM) of single perovskite quantum dots. New study shows that single perovskite quantum dots could be a fundamental building block for quantum-photonic technologies for computing or communications.

Quantum dots can spit out clone-like photons

System that generates coherent single particles of light could help pave the way for quantum information processors or communications.

February 21, 2019

The quasar dates back to less than one billion years after the big bang.

Light from ancient quasars helps confirm quantum entanglement

Results are among the strongest evidence yet for “spooky action at a distance.”

August 19, 2018

Scientists at MIT have found a way to visualize electron behavior beneath a material’s surface. The team’s technique is based on quantum mechanical tunneling, a process by which electrons can traverse energetic barriers by simply appearing on the other side. In this image, researchers show the measured tunneling spectra at various densities, with high measurements in red.

A new window into electron behavior

Scientists invent technique to map energy and momentum of electrons beneath a material’s surface.

November 16, 2017

When electrons travelling individually pass through a constricted opening, they will bounce off the walls at either side, losing their momentum as well as some of their energy. But when the electrons travel in dense groups, they are much more likely to bounce off each other than the walls, and travel quickly.

Experiments confirm theory of “superballistic” electron flow

Behaving like particles in a viscous fluid can help bunches of electrons squeeze through a tight space.

August 23, 2017

Mapping the effects of crystal defects

Study sheds light on interactions that change the way heat and electricity move through microchips.

March 14, 2017

New research shows that electrons passing through a narrow constriction in a piece of metal can move much faster than expected, and that they move faster if there are more of them — a seemingly paradoxical result. In this illustration, the orange surface represents the potential energy needed to get an electron moving, and the “valley” at center represents the constricted portion.

Electrons go superballistic

Newly discovered phenomenon accelerates electrons as they enter a viscous state.

March 6, 2017

Physicists from MIT, the University of Vienna, and elsewhere have presented a strong demonstration of quantum entanglement even when vulnerability to the freedom-of-choice loophole is significantly restricted.

Stars align in test supporting “spooky action at a distance”

Physicists address loophole in tests of Bell’s inequality, using 600-year-old starlight.

February 6, 2017

MIT professor of physics Senthil Todadri seeks to understand unusual metals that defy the textbook description. “We’ve been making slow but steady progress, not just I, myself, but the community as a whole, but I would really like that progress to accelerate,” he says.

Faculty highlight: Senthil Todadri

A quest to understand superconductivity leads MIT theoretical physicist Senthil Todadri to discoveries about new magnetic materials called quantum spin liquids.