Transistors, the building blocks of modern electronics, are typically made of silicon. Because it’s a semiconductor, this material can control the flow of electricity in a circuit. But silicon has fundamental physical limits that restrict how compact and energy-efficient a transistor can be.

MIT researchers have now replaced silicon with a magnetic semiconductor, creating a magnetic transistor that could enable smaller, faster, and more energy-efficient circuits. The material’s magnetism strongly influences its electronic behavior, leading to more efficient control of the flow of electricity. 

The team used a novel magnetic material and an optimization process that reduces the material’s defects, which boosts the transistor’s performance.

The material’s unique magnetic properties also allow for transistors with built-in memory, which would simplify circuit design and unlock new applications for high-performance electronics.

“People have known about magnets for thousands of years, but there are very limited ways to incorporate magnetism into electronics. We have shown a new way to efficiently utilize magnetism that opens up a lot of possibilities for future applications and research,” says Chung-Tao Chou, an MIT graduate student in the departments of Electrical Engineering and Computer Science (EECS) and Physics, and co-lead author of a paper on this advance.

Chou is joined on the paper by co-lead author Eugene Park, a graduate student in the Department of Materials Science and Engineering (DMSE); Julian Klein, a DMSE research scientist; Josep Ingla-Aynes, a postdoc in the MIT Plasma Science and Fusion Center; Jagadeesh S. Moodera, a senior research scientist in the Department of Physics; and senior authors Frances Ross, TDK Professor in DMSE; and Luqiao Liu, an associate professor in EECS, and a member of the Research Laboratory of Electronics; as well as others at the University of Chemistry and Technology in Prague. The paper appears today in Physical Review Letters.

Overcoming the limits

In an electronic device, silicon semiconductor transistors act like tiny light switches that turn a circuit on and off, or amplify weak signals in a communication system. They do this using a small input voltage.

But a fundamental physical limit of silicon semiconductors prevents a transistor from operating below a certain voltage, which hinders its energy efficiency.

To make more efficient electronics, researchers have spent decades working toward magnetic transistors that utilize electron spin to control the flow of electricity. Electron spin is a fundamental property that enables electrons to behave like tiny magnets.

So far, scientists have mostly been limited to using certain magnetic materials. These lack the favorable electronic properties of semiconductors, constraining device performance.

“In this work, we combine magnetism and semiconductor physics to realize useful spintronic devices,” Liu says.

The researchers replace the silicon in the surface layer of a transistor with chromium sulfur bromide, a two-dimensional material that acts as a magnetic semiconductor.

Due to the material’s structure, researchers can switch between two magnetic states very cleanly. This makes it ideal for use in a transistor that smoothly switches between “on” and “off.”

“One of the biggest challenges we faced was finding the right material. We tried many other materials that didn’t work,” Chou says.

They discovered that changing these magnetic states modifies the material’s electronic properties, enabling low-energy operation. And unlike many other 2D materials, chromium sulfur bromide remains stable in air.

To make a transistor, the researchers pattern electrodes onto a silicon substrate, then carefully align and transfer the 2D material on top. They use tape to pick up a tiny piece of material, only a few tens of nanometers thick, and place it onto the substrate.

“A lot of researchers will use solvents or glue to do the transfer, but transistors require a very clean surface. We eliminate all those risks by simplifying this step,” Chou says.

Leveraging magnetism

This lack of contamination enables their device to outperform existing magnetic transistors. Most others can only create a weak magnetic effect, changing the flow of current by a few percent or less. Their new transistor can switch or amplify the electric current by a factor of 10.

They use an external magnetic field to change the magnetic state of the material, switching the transistor using significantly less energy than would usually be required.

The material also allows them to control the magnetic states with electric current. This is important because engineers cannot apply magnetic fields to individual transistors in an electronic device. They need to control each one electrically.

The material’s magnetic properties could also enable transistors with built-in memory, simplifying the design of logic or memory circuits.

A typical memory device has a magnetic cell to store information and a transistor to read it out. Their method can combine both into one magnetic transistor.

“Now, not only are transistors turning on and off, they are also remembering information. And because we can switch the transistor with greater magnitude, the signal is much stronger so we can read out the information faster, and in a much more reliable way,” Liu says.

Building on this demonstration, the researchers plan to further study the use of electrical current to control the device. They are also working to make their method scalable so they can fabricate arrays of transistors.

This research was supported, in part, by the Semiconductor Research Corporation, the U.S. Defense Advanced Research Projects Agency (DARPA), the U.S. National Science Foundation (NSF), the U.S. Department of Energy, the U.S. Army Research Office, and the Czech Ministry of Education, Youth, and Sports. The work was partially carried out at the MIT.nano facilities.

Nice video of the Arctic bobtail squid.

As usual, you can also use this squid post to talk about the security stories in the news that I haven’t covered.

Blog moderation policy.

Through data brokers, ICE is buying the information you provided to open a credit card.

A fight over USDA immigration and diversity policies held up $15 million in wildfire-prevention grants for an area in Washington state that’s now burning.

Occidental Petroleum's project in West Texas was supposed to start in late 2024. Scientists say carbon removal is essential to slowing climate change.

The half-dozen lawmakers will lead the conversation on shaping the Assembly’s priorities on the issue.

The confirmation of Cameron Hamilton, nominee to lead FEMA, means he'll be in place for peak hurricane season.

The extreme weather has prompted health warnings for millions of people in several countries.

Climate change is making it costlier for Malaysian growers to produce quality durians, adding pressure as they compete with Thailand and Vietnam, which dominate a booming export market to China.

To facilitate this aim, Turkey confirmed it had joined the Coalition to Grow Carbon Markets, an initiative formed to bolster corporate demand for high-integrity carbon credits.

The company will benefit from its wide renewables portfolio, which ranges from wind turbine manufacturing to battery production.

A tall glass of ice water isn’t just a thirst quencher; it’s also an everyday example of coexisting phases. Water’s molecular makeup can exist simultaneously in both a liquid and solid phase. And as it turns out, this phase duality can exist in more exotic, quantum materials, and in ways that are far more complicated to tease apart. 

A new study by MIT physicists sheds light on how two different phases of electron behavior can emerge and coexist in the same quantum material. 

Their results, reported today in the journal Nature Physics, can help to explain how some materials host superconductivity, magnetism, and other electronic phases. Untangling such phases, and understanding how they emerge, will help engineers control electronic behavior and design high-performance quantum devices. 

“People believe the cornerstone of replacing silicon lies in quantum materials that have multiple coexisting phases,” says co-author Alfred Zong PhD ’20, who co-led the study as an MIT graduate student and is now an assistant professor at Stanford University. “Our experiment provides a very neat way to study these multiple phases.”

The team, led by Nuh Gedik, the Donner Professor of Physics at MIT, studied the rare-earth material erbium tritelluride. As with most materials, erbium tritelluride’s electrons are normally scattered uniformly throughout the material. But when cooled to certain temperatures, the electrons suddenly organize into a wave-like pattern, which physicists term a “charge density wave” (CDW) phase. When cooled even further, electrons coordinate again as a second wavy phase that criss-crosses the first. The effect is of an atomic checkerboard of co-existing electron phases. 

Now, Gedik and his colleagues have teased apart erbium tritelluride’s phases and observed how each phase emerges. They found that one phase forms gradually, similar to how liquid water transitions uniformly into vapor. This is the classic, textbook way in which electronic phase transitions are thought to occur.

But the second phase came about in an entirely new and unexpected way: Instead of emerging gradually, the electrons organized first in pockets that eventually expanded, similar to how liquid water crystallizes into ice. 

“The mechanism responsible for the emergence of this second phase has long been debated, and our approach provides a powerful new way to uncover the hidden physics behind phase transitions in quantum materials,” Gedik says.

The study’s other MIT co-authors are first authors Yifan Su PhD ’24 and Bai-Qing Lv, a former postdoc; Dongsung Choi SM ’17, PhD ’24; and former postdocs Doron Azoury and Masataka Mogi; along with collaborators from multiple other institutions.

A clear view

A charge density wave is made up of charges, such as electrons, that spontaneously organize as a wave. The wave’s crests hold the highest density of electrons, and the lowest are found in the troughs. In some materials, electrons transition into this strange coordinated phase at super-cold temperatures. 

Scientists have observed charge density waves for decades, and most recently in materials that also host other, more complicated forms of electron coordination, such as various forms of magnetism, and superconductivity, in which electrons pair up and flow through a material without friction. 

“Just like superconductivty, charge density waves are a collective phenomena where electrons move together in certain ways,” explains lead author Yifan Su. “The power of CDWs is that they are a much simpler form of matter compared to superconductivity. They offer a playground for fundamental understanding.”

Su and the team looked to get a clear view of charge density waves in a material that hosts two CDW phases simultaneously. How these waves emerge and coexist in a single material could shed light on how superconductivity and other more complicated phase transitions occur. 

“One of the biggest questions in physics is why some materials host multiple phases while others do not. And when multiple phases do exist, how do they interact? Do they reinforce one another, compete, or coexist independently?” Gedik says. “This is like a case study for us to understand much more complicated materials.”

Shake, then listen

Scientists have observed two different charge density waves in erbium tritelluride — a rare-earth material that can be synthesized in the lab, in atomically thin sheets that can then be probed for unique, quantum-scale properties. 

In previous experiments, physicists have found that when erbium tritelluride is cooled down to -8 degrees Celsius, the first of two charge density waves forms among the material’s electrons. This “dominant” wave stretches across the material in one direction. When the material is further cooled to -113 degrees Celsius, a second, “subdominant” charge density wave emerges, perpendicular to the first, creating a checkerboard of coexisting electronic phases. 

In their new study, Gedik and his colleagues sought to tease out how each phase emerges in erbium tritelluride. The team obtained small, atomically thin samples of the material, which were synthesized by collaborators at Stanford. In Gedik’s lab, the researchers then cooled the samples down to about -230 degrees Celsius — temperatures at which the material should host both charge density waves, in a simultaneous, checkerboard pattern. They then either destroyed or weakened the checkerboard, and watched how both types of waves reemerged. 

To do so, they exposed each cooled sample to a one-two punch of laser pulses. 

“This is how we ‘shake’ and then ‘listen’ to the system,” Gedik says.

The first pulse was the “shake” that dissolved the checkerboard. The researchers could control the intensity of this kick to vary the degree to which the waves were disturbed. They then delivered a second laser pulse, of high-energy photons, to kick out electrons from the material. This second pulse was sent in at various times after the first pulse. The researchers then measured the energy and momentum of the kicked-out electrons, to get snapshots of how the material’s electronic phases recovered. 

“We see the destroying of these phases, and then if we wait long enough, they come back,” Gedik explains. “And depending on how you hit them, the two phases respond differently.”

From their experiments, the team found that the first, dominant phase of charge density waves reemerges gradually and uniformly, no matter how hard the material was initially “kicked.” This smooth restoration is a textbook, “second-order” phase transition, similar to a magnet gradually losing its magnetism as it is heated.

What was more surprising was how the second wave pattern reemerged. This subdominant phase reformed more like water into ice. The electrons reassembled the wave in isolated pockets that spread, like crystals of ice. This more rare, “first-order” transition was not expected. The team’s study captured the the long-debated mechanism underlying the emergence of the subdominant CDW phase. 

“In systems that are much more complex, like high-temperature superconductors, you see there are multiple phases — magnetism, superconductivity, charge density waves, and they all exist together,” Gedik says. “One of the theories is that, the way they interact with each other is key for their exotic properties. The lessons we learn here can be applied to much more complex materials.”

This work was supported by the U.S. Department of Energy, the U.S. National Science Foundation, and the Gordon and Betty Moore Foundation’s EPiQS Initiative grant.

MIT has appointed Akirah Bradley-Armstrong as vice chancellor for student life, effective Oct. 19, 2026. 

The appointment, following a national search, was announced yesterday in a letter sent to the MIT community from Chancellor Melissa Nobles, to whom Bradley-Armstrong will report. Bradley-Armstrong will succeed Vice Chancellor for Student Life Suzy M. Nelson, who transformed student life at MIT during her 10 years in the role. Nelson announced her retirement earlier this year.

Bradley-Armstrong joins MIT from the University of California at Santa Cruz, where she has served as vice chancellor for student affairs and success since 2022. In that role, she has led one of the university's largest divisions, overseeing approximately 800 professional staff, 2,100 student employees, and more than 30 departments dedicated to supporting student success, health and wellness, housing, athletics, recreation, and campus life. She has served as a principal advisor to UCSC’s chancellor on student issues and collaborated with the academic deans, faculty, and the campus provost on student initiatives. 

“Akirah is an accomplished and compassionate leader whose commitment to student success, belonging, and well-being has been demonstrated throughout her career,” says Nobles. “She brings a deep understanding of the challenges students face today, extensive expertise leading complex organizations, and a collaborative approach that will help her continue the work we have done to strengthen the student experience at MIT.”

The Office of the Chancellor oversees student life and learning at MIT. In her new role, Bradley-Armstrong will lead the student life side of that mission for undergraduate and graduate students. This broad portfolio encompasses dining; well-being and support; student organizations and events; the Department of Athletics, Physical Education and Recreation; and living communities, including oversight of the faculty-led residential house system. 

Before assuming her current role at UC Santa Cruz, Bradley-Armstrong was the vice chancellor for student affairs at the University of Colorado at Boulder and held senior student life roles at the University of California at Berkeley. Bradley-Armstrong is a nationally recognized leader in higher education who served on the board of the National Association of Student Personnel Administrators and chaired its 2025 national conference.

“Throughout my career, I have partnered with high-achieving students across multiple institutions and understand that extraordinary achievement must be paired with strong investments in well-being, mental health, and belonging,” says Bradley-Armstrong. “I’m particularly energized by MIT’s large graduate student population, having worked with graduate students on housing, childcare, and student support, while also teaching a graduate course at CU Boulder. I’m equally drawn to MIT's residential house system, which clearly plays a critical role in the lives of students.”

Bradley-Armstrong has extensive experience leading institutions through periods of change and responding to complex student issues. She has collaborated with campus partners to develop policies and programs that promote dynamic campus communities. Grounded in her background as a first-generation college graduate, student-athlete, and sorority member, Bradley-Armstrong has earned a reputation for leading with deep integrity and an unshakeable commitment to student success. 

“I am honored to join MIT and to serve alongside its students, faculty, and staff to support an exceptional student experience,” Bradley-Armstrong says. “MIT has a remarkable tradition of innovation, excellence, and community. I look forward to listening, learning, and building on the Institute's strong commitment to helping every student thrive.”

Nobles notes, “Throughout her career, Akirah has driven high-impact, system-level change across residential and Greek life, dining, athletics, and campus planning. Her innovative approach led to the launch of the University of California system’s first campus mobile crisis response team, the establishment of a two-year housing guarantee, and the advancement of initiatives of the UC Santa Cruz strategic plan.”

Bradley-Armstrong earned a Doctor of Education in Educational Leadership from the University of California at Davis. Her doctoral research examined how universities respond to tragedy as well as the support systems that help administrators navigate crisis response and recovery. She also holds a Master of Education in Higher Education and Student Affairs Administration from the University of Vermont, and a bachelor's degree from Mansfield University. 

“I look forward to welcoming Akirah to MIT and to working alongside her — and our whole community — to shape MIT’s next chapter of student life,” says Nobles.

There are many companies manufacturing adversarial clothing designed to confuse facial recognition systems.

It’s a cool idea, but I worry that it’s mostly security theater:

“Our patterns play with that chaos, confuse algorithms and make it way harder to pin you down,” he said.

Bell, however, said “none of these products are tried and tested, and a lot of these surveillance technologies can deal with a little resistance … [but] even if the designs don’t necessarily work perfectly, fashion is also a visible sign of resistance.

“This is consumers collectively coming together to make a visible statement.”...

The country has become a top purchaser of solar panels amid soaring energy prices and supply concerns. “Now is the time,” an analyst says.

A new study finds that global warming made this summer's fire conditions more likely to occur — not Canadian forest management.

Leaders of four Northeastern states asked Trump to reconsider denying them $227 million to recover from a February snowstorm.

Global warming, not climate policy, is bad for business, experts warn.

"Just like human beings, jet engines require lots of cool, dense air to perform well," said the CEO of Aero Consulting Experts.

South Korean President Lee Jae Myung instructed officials to view the ongoing heat wave as "a national disaster." In Japan, three lions died at a Tokyo zoo.