For thirty-three years, one number refused to move. In 1993, a mercury-based ceramic called Hg1223 was shown to lose all electrical resistance at 133 kelvin, roughly minus 140 degrees Celsius. That figure became the ceiling for what any material could do at ordinary atmospheric pressure, and it stayed there while an entire generation of condensed-matter physicists came and went.
In March 2026, the ceiling moved. A team at the University of Houston and its Texas Center for Superconductivity reported that the same mercury cuprate, treated with a technique called pressure quenching, superconducts at 151 kelvin once the pressure is taken away. Eighteen degrees does not sound dramatic. In a field that had been flat since the Clinton administration, it was the largest single jump in decades, and it reopened a question most researchers had quietly set aside: is a superconductor that works at room temperature, in a normal room, actually reachable?
What a superconductor is, and why the temperature matters so much
Push current through ordinary copper wire and some of it turns into heat. That loss is resistance, and it is why electrical grids waste roughly five to eight percent of everything they carry between the generator and the wall socket. A superconductor has no resistance at all below a certain temperature, known as the critical temperature or Tc. Current placed in a superconducting loop will circulate indefinitely without fading.
The catch has always been the cold. The first superconductor, mercury, needed 4.2 kelvin, colder than the surface of Pluto. The cuprate ceramics discovered in the late 1980s pushed the threshold above the boiling point of liquid nitrogen at 77 kelvin, which is cheap and abundant, and that alone was enough to make superconducting magnets commercially viable for MRI machines and particle accelerators. But 77 kelvin is still minus 196 Celsius. Every superconducting device in operation today sits inside a cryostat, and the cryostat is usually the expensive part.
A room-temperature superconductor would remove the cryostat. That is the whole prize.
The March 2026 result: locking in high pressure after removing it
Physicists have known for a long time that squeezing a superconductor raises its Tc. Compression shortens the distance between atoms and stiffens the lattice vibrations that help electrons pair up. The problem is that the effect vanishes the instant the pressure is released, which makes it a laboratory curiosity rather than a technology.
Pressure quenching attacks that problem sideways. The Houston group compressed HgBa2Ca2Cu3O8+δ to raise its transition temperature, then cooled the sample while it was still under load, then released the pressure abruptly. The lattice, already frozen into its compressed geometry, had no thermal energy left to relax back. The enhanced state survived at ambient pressure, and the material superconducted at 151 kelvin. The work was published in the Proceedings of the National Academy of Sciences and independently written up by the American Physical Society.
It is worth being precise about what this does and does not show. 151 kelvin is minus 122 Celsius. It is not room temperature and nobody involved claimed it was. What it demonstrates is that the enhancement from pressure can be made to persist, which had never been shown at this scale before. If the trick generalises to other materials, the pressure barrier stops being a permanent obstacle and becomes an engineering step.
The hydride race, and why its records come with an asterisk
The other half of the field works on hydrogen-rich compounds under crushing pressure. Hydrogen is the lightest element, its lattice vibrations are the fastest, and theory has predicted since the 1960s that metallic hydrogen should superconduct near room temperature. Nobody has made bulk metallic hydrogen, but hydrides get partway there.
Lanthanum hydride, LaH10, superconducts at roughly 250 to 260 kelvin under 170 to 190 gigapascals. That is around minus 15 Celsius, genuinely close to room temperature, and it has been reproduced by multiple groups. The pressure, however, is about two million times atmospheric, achievable only in a diamond anvil cell holding a sample the width of a human hair.
More recent claims go further. A Chinese group reported superconductivity with an onset near 298 kelvin in a lanthanum-scandium hydride formed with ammonia borane at 250 to 260 gigapascals. That is room temperature by any definition, but at pressures found near the centre of the Earth, and independent replication is still outstanding. The field has been burned before. A 2020 room-temperature claim in a carbonaceous sulfur hydride was retracted by Nature, and a separate 2023 claim collapsed under scrutiny within months. Caution here is earned, not reflexive.
Where the records actually stand
| Material | Critical temperature | Pressure required | Status |
|---|---|---|---|
| Mercury (Hg) | 4.2 K | Ambient | Original 1911 discovery |
| YBCO cuprate | 92 K | Ambient | In commercial use |
| Hg1223 cuprate | 133 K | Ambient | Record from 1993 to 2026 |
| Hg1223, pressure-quenched | 151 K | Ambient after quench | Current ambient-pressure record, 2026 |
| LaH10 | 250-260 K | 170-190 GPa | Replicated |
| La-Sc hydride | ~298 K claimed | 250-260 GPa | Awaiting independent replication |
Why pressure is the harder problem than temperature
Public attention fixes on the temperature figure because it is easy to compare against a thermometer. Inside the field, the pressure column of that table is the one that decides whether anything becomes a product. A material that needs 200 gigapascals cannot be drawn into wire, wound into a coil, or buried under a street. Diamond anvil samples are measured in micrograms.
This is why the Houston result drew attention out of proportion to its 18-degree gain. It is the first credible demonstration that the pressure enhancement and the pressure requirement can be separated. Whether pressure quenching works on hydrides, which are far less stable than cuprates, is unknown and is the obvious next experiment.
Canada’s stake in the quantum-materials question
Canadian groups sit closer to this problem than their public profile suggests. The Stewart Blusson Quantum Matter Institute at the University of British Columbia, the Institut quantique at the Université de Sherbrooke, and Transformative Quantum Technologies at the University of Waterloo all hold Canada First Research Excellence Fund support and now coordinate through a joint programme called Quantum Colab. Sherbrooke and UBC have published together on the pseudogap phase of cuprates, the still-unexplained regime that sits directly above the superconducting state in exactly the mercury-based family that produced the 2026 record.
The surrounding investment is substantial. Quebec committed close to 200 million dollars to quantum research and development between 2019 and 2026, including 131 million for the Sherbrooke quantum innovation institute. The Waterloo corridor known as Quantum Valley hosts more than twenty quantum companies and institutions and has drawn over 1.5 billion dollars in related investment. Cuprate physics is not the headline application for any of that money, but the experimental infrastructure and the theory groups overlap almost completely.
What actually changes if it works
The realistic near-term payoff is not levitating trains. It is transmission. Grid losses of five to eight percent are a permanent tax on every electron generated, and eliminating them would do more for emissions than most technologies currently subsidised for that purpose. Superconducting cables already exist in short demonstration runs in Germany, South Korea and the United States, limited by the cost of keeping them cold.
After that come magnets. Tokamak fusion reactors, MRI scanners, and the beam optics in particle accelerators all consume large fractions of their budgets on cryogenics. Removing that constraint changes the economics of fusion in particular, where magnet cost is a first-order term.
Consumer applications, the lossless laptops and floating skateboards that appear whenever a superconductor story goes viral, are the least likely outcome and the least interesting one. Resistance in a phone is not what limits a phone.
Frequently asked questions
Has anyone made a room-temperature superconductor?
Not one that has been independently confirmed and works at ordinary pressure. A Chinese group has claimed superconductivity near 298 kelvin in a lanthanum-scandium hydride, but only at 250 to 260 gigapascals and without replication elsewhere. The verified ambient-pressure record is 151 kelvin, set in March 2026.
What is the highest temperature superconductor as of 2026?
At ambient pressure, pressure-quenched HgBa2Ca2Cu3O8+δ at 151 kelvin. Under extreme pressure, LaH10 at 250 to 260 kelvin is the highest figure that multiple independent groups have reproduced.
Why do superconductors need to be so cold?
Superconductivity depends on electrons pairing up and moving as a single coherent quantum state. Heat is atomic motion, and above the critical temperature that motion carries enough energy to break the pairs apart. Raising Tc means finding materials where the pairing is strong enough to survive more thermal disruption.
What would room-temperature superconductors be used for first?
Power transmission and large magnets. Both are applications where the cost of cryogenic cooling currently dominates, so removing it changes the economics immediately. Fusion reactor magnets and long-distance grid cables are the two clearest candidates.
Are superconductor breakthroughs usually real?
The record is mixed and worth knowing. A 2020 room-temperature claim in carbonaceous sulfur hydride was retracted, and a widely publicised 2023 ambient-pressure claim failed replication within months. Results that survive scrutiny, such as the 2026 Houston work, are published in peer-reviewed venues and reproduced by other laboratories before the field treats them as settled.
Where this leaves the question
The honest answer in 2026 is that room-temperature superconductivity at usable pressure remains unsolved, and that the field is in a better position than it has been in three decades. Two separate lines of attack are converging: hydrides that reach the right temperature at impossible pressure, and a new technique that can make pressure enhancements permanent. Neither alone is the answer. The interesting question is whether they can be combined.
Related reading on this site: quantum theory and its limits, the perovskite-silicon tandem efficiency record, and higher dimensions in physics.
