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.

A small team of researchers who dispute mainstream climate science may play an outsize role in the next National Climate Assessment.

New York and Hawaii could expand the legal battlefield and seek to hold companies liable for disasters that cause premiums to rise.

A win for oil companies in the case could help them avoid paying billions of dollars to fund restoration.

New York Attorney General Letitia James (D) said the administration's stop-work order lacks reason and justification.

Offshore energy regulators have issued a 90-day construction pause on Revolution Wind and four other projects.

The Trump administration eliminated grants to hundreds of projects for infrastructure and climate adaptation in underserved communities.

Investment funds’ net-long position on carbon is near the highest in data going back to early 2018 shows.

The caution comes as President Donald Trump pulls the U.S. out of key global climate organizations.

Increasingly, manufacturers are making toilet paper from recycled paper products, which avoids material from freshly cut trees.

Nature Climate Change, Published online: 12 January 2026; doi:10.1038/s41558-025-02542-4

The authors quantify long-term (2003–2024) changes in Northern Hemisphere mountain aspect asymmetry—the difference in vegetation density between polar-facing and equatorial-facing slopes. They show a weakening trend, linked to changing hydrothermal conditions.

Going to the moon was one thing; going to Mars will be quite another. The distance alone is intimidating. While the moon is 238,855 miles away, the distance to Mars is between 33 million and 249 million miles. The propulsion systems that got us to the moon just won’t work.

Taylor Hampson, a master’s student in the Department of Nuclear Science and Engineering (NSE), is well aware of the problem. It’s one of the many reasons he’s excited about his NASA-sponsored research into nuclear thermal propulsion (NTP).

The technique uses nuclear energy to heat a propellant, like hydrogen, to an extremely high temperature and expel it through a nozzle. The resultant thrust can significantly reduce travel times to Mars, compared to chemical rockets. “You can get double the efficiency, or more, from a nuclear propulsion engine with the same thrust. Besides, being in microgravity is not ideal for astronauts, so you want to get them there faster, which is a strong motivation for using nuclear propulsion over the chemical equivalents,” Hampson says.

Understanding nuclear thermal propulsion

It’s worth taking a quick survey of rocket propulsion techniques to understand where Hampson’s work fits.

There are three broad types of rocket propulsion: chemical, where thrust is achieved by the combustion of rocket propellants; electrical, where electric fields accelerate charged particles to high velocities to achieve thrust; and nuclear, where nuclear energy delivers needed propulsion.

Nuclear propulsion, which is only used in space, not to get to space, further falls into one of two categories: nuclear electric propulsion uses nuclear energy to generate electricity and accelerate the propellant. Nuclear thermal propulsion, which is what Hampson is researching, heats a propellant using nuclear power. A significant advantage of NTP is that it can deliver double the efficiency (or more) of the chemical equivalent for the same thrust. A disadvantage: cost and regulatory hurdles. “Sure, you can get double the efficiency or more from a nuclear propulsion engine, but there hasn’t been a mission case that has needed it enough to justify the higher cost,” Hampson says.

Until now.

With a human mission to Mars becoming a very real possibility — NASA plans on sending astronauts to Mars as early as the 2030s — NTP might soon come under the spotlight.

"It's almost futuristic"

Growing up on Florida’s Space Coast and watching space shuttle launches stoked Hampson’s early interest in science. Loving many other subjects, including history and math, it wasn’t until his senior year that Hampson cast his lot into the engineering category. While space exploration got him hooked on aerospace engineering, Hampson was also intrigued by the possibility of nuclear engineering as a way to a greener future.

Wracked by indecision, he applied to schools in both fields and completed his undergraduate degree in aerospace engineering from Georgia Tech. It was here that a series of internships in space technology companies like Blue Origin and Stoke Space, and participation in Georgia Tech’s rocket team, cemented Hampson’s love for rocket propulsion.

Looking to pursue graduate studies, MIT seemed like the next logical step. “I think MIT has the best combination of nuclear and aerospace education, and is really strong in the field of testing nuclear fuels,” Hampson says. Facilities in the MIT Reactor enable testing of nuclear fuel under conditions they would see in a nuclear propulsion engine. It helped that Koroush Shirvan, associate professor of NSE and Atlantic Richfield Career Development Professor in Energy Studies, was working on nuclear thermal propulsion efforts with NASA while focusing most of his efforts on the testing of nuclear fuels.

At MIT, Hampson works under the advisement of Shirvan. Hampson has had the chance to pursue further research in a project he started with an internship at NASA: studies of a nuclear thermal propulsion engine. “Nuclear propulsion is itself advanced, and I’m working on what comes after that. It’s almost futuristic,” he says.

Modeling the effects of nuclear thermal propulsion

While the premise of NTP sounds promising, its execution will likely not be straightforward. For one thing, with NTP, the rocket engine won’t start up and shut down like simple combustion engines. The startup is complex because rapid increase in temperatures can cause material failures. And the engines can take longer to shut down because of heat from nuclear decay. As a result, the components have to continue to be cooled until enough fission products decay away so there isn’t a lot of heat left, Hampson says.

Hampson is modeling the entirety of the rocket engine system — the tank, the pump, and more — to understand how these and many other parameters work together. Evaluating the entire engine is important because different configurations of parts (and even the fuel) can affect performance. To simplify calculations and to have simulations run faster, he’s working with a relatively simple one-dimensional model. Using it, Hampson can follow the effects of variables on parameters like temperature and pressure on each of the components throughout the engine operation.

“The challenge is in coupling the thermodynamic effects with the neutronic effects,” he says.

Ready for more challenges ahead

After years of indecision, delaying practically every academics-related decision to the last minute, Hampson seems to have zeroed in on what he expects to be his life’s work — inspired by the space shuttle launches many years ago — and hopes to pursue doctoral studies after graduation.

Hampson always welcomes a challenge, and it’s what motivates him to run. Training for the Boston Marathon, he fractured his leg, an injury that surfaced when he was running for yet another race, the Beantown Marathon. He’s not bowed by the incident. “I learned that you’re a lot more capable than you think,” Hampson says, “although you have to ask yourself about the cost,” he laughs. (He was in crutches for weeks after).

A thirst for a challenge is also one of the many reasons he chose to research thermal nuclear propulsion. It helps that the research indulges his love for the field. “Relatively speaking, it’s a field in need of much more advancement; there are many more unsolved problems,” he says. 

The latest article on this topic.

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.

MIT is often recognized as one of the leading institutions of higher learning not only in the United States, but in the world, by several publications, including U.S. News & World Report, QS World University Rankings, Times Higher Education, and Forbes.

Now, MIT also has the distinction of being one of just 30 colleges and universities out of hundreds recognized by Princeton Review’s 2026 Mental Health Services Honor Roll for providing exemplary mental health and well-being services to its students. This is the second year in a row that MIT has received this honor.

The honor roll was created to be a resource for enrolled students and prospective students who may seek such services when applying to colleges. The survey asked more than a dozen questions about training for students, faculty, and staff; provisions for making new policies and procedures; peer-to-peer offerings; screenings and referral services available to all students; residence hall mental health resources; and other criteria, such as current online information that is updated and accessible.

Overall, the 2025 survey findings for all participating institutions are noteworthy, with Princeton Review reporting double-digit increases in campus counseling, wellness, and student support programs compared with its 2024 survey results. Earning a place on the honor roll underscores MIT’s commitment to providing exceptional services for graduate and undergraduate students alike.

Karen Singleton, deputy chief health officer and chief of mental health and counseling services at MIT Health, says, “This honor highlights the hard work and collaboration that we do here at MIT to support students in their well-being journey. This is a recognition of how we are doing those things effectively, and a recognition of MIT’s investment in these support services.”

MIT Health hosts 36 clinicians to meet the needs of the community, and it recently added an easy online scheduling system at the request of students.

Many mental health and well-being services are offered through several departments housed in the Division of Student Life (DSL). They often collaborate with MIT Health and partners across the Institute, including in the Division of Graduate and Undergraduate Education, to provide the best services for the best outcomes for MIT students. 

Support resources in DSL are highly utilized and valued by students. For instance, 82 percent of the Class of 2025 had visited Student Support Services (S3) at least once before graduating, and on a regular satisfaction survey, 91 percent of students who visited S3 said they would return if needed.

“Student Support Services supports over 80 percent of all undergraduates by the time they graduate, and over 60 percent each year. Our offices, including ORSEL, GradSupport, S3, SMHC, the CARE Team, and Residential and Community Life work incredibly well together to support our students,” says Kate McCarthy, senior associate dean of support, wellbeing, and belonging.

“The magic in our support system is the deeply collaborative nature of it. There are many different places students can enter the support network, and each of these teams works closely together to ensure students get connected to the help they need. We always say that students shouldn’t think too much about where they turn … if they get to one of us, they get to all of us,” says David Randall, dean of student life.

Division of Student Life Vice Chancellor Suzy Nelson adds, “It is an honor to see MIT included among colleges and universities recognized for excellent mental health services. Promoting student well-being is central to our mission and guides so much of what we do. This recognition reflects the work of many in our community who are dedicated to creating a campus environment where students can thrive academically and personally.”

Palo Alto’s crosswalk signals were hacked last year. Turns out the city never changed the default passwords.

Withdrawing from the world’s premier climate science organization supports the president’s views about global warming.

The prospect of ramping up the country’s heavy crude production goes against global efforts to phase down fossil fuels.

“We might as well focus on what we can control,” said Environment and Public Works Chair Shelley Moore Capito (R-W.Va.).

The justice holds stock in an oil company that withdrew from the lawsuit right before the high court took up the case.

Beset by crises in Ukraine and Greenland, leaders let the U.S. withdrawal from the world’s most important climate body pass with barely a mention.