Strontium titanate’s remarkable ability to perform at extremely low temperatures makes it a key material for next-generation cryogenic devices used in quantum computing and space exploration.
Superconductivity and quantum computing have moved beyond theoretical research to capture the public’s imagination. The 2025 Nobel Prize in Physics recognized breakthroughs in superconducting quantum circuits, a key step toward developing ultra-powerful computers. Yet many may not realize that such cutting-edge technologies typically function only at cryogenic temperatures, near absolute zero. Under these extreme conditions, most materials lose their defining physical properties, making practical progress a major challenge.
A recent study in Science by engineers at Stanford University highlights a material that could overcome this limitation: strontium titanate (STO). Unlike most substances, STO’s optical and mechanical properties not only endure the cold but actually improve, far exceeding the performance of comparable materials. The research team suggests that STO could serve as a foundation for a new generation of light-based and mechanical devices designed to operate in cryogenic environments, advancing fields such as quantum computing and space exploration.
Strontium titanate has electro-optic effects 40 times stronger than the most-used electro-optic material today. But it also works at cryogenic temperatures, which is beneficial for building quantum transducers and switches that are current bottlenecks in quantum technologies,” explained the study’s senior author Jelena Vuckovic, a professor of electrical engineering.
Peak performance
STO’s photonic effects are described as “non-linear.” That is, when an electric field is applied, STO changes its optical and mechanical properties significantly. The optical nonlinearity (the electro-optic effect) in STO can be used to change the frequency, phase, intensity, and the bending of light in ways and to degrees other materials cannot. Engineers can harness these effects to create new low-temperature devices not possible otherwise.
STO is also piezoelectric, meaning it expands and contracts physically when an electric field is applied, opening the possibility of new electromechanical devices that operate at cryogenic temperatures, as well. The researchers noted these observations could make STO particularly valuable in the cold expanses of outer space or in the cryogenic fuel tanks of rockets.
“At low temperature, not only is strontium titanate the most electrically tunable optical material we know of, but it’s also the most piezoelectrically tunable material, emphasized co-first author Christopher Anderson, a former postdoctoral scholar in Vuckovic’s lab who is now on faculty at the University of Illinois, Urbana-Champaign.
Wallflower at the dance
STO is not new. It has been well studied for decades, but never in the context of cryogenic, electrically controlled optics. “STO is not particularly special. It’s not rare. It’s not expensive,” says co-first author Giovanni Scuri, a postdoctoral scholar in Vuckovic’s lab. “In fact, it has been often used as a diamond substitute in jewelry or as a growth substrate for other, more valuable materials. Despite being a ‘textbook’ material studied for decades, it performs exceptionally in a cryogenic context.”
Choosing STO did not result from an exhaustive search of potential candidates, but neither was it an accident, Anderson explained. “We knew what ingredients we needed to make a highly tunable material. We found that those ingredients already existed in nature, and we simply used them in a new recipe. STO was the obvious choice,” he said. “When we tried it, surprisingly, it matched our expectations perfectly.”
From there, the team developed an understanding of how to optimize materials for different operating conditions, Scuri said, adding: “The ideas we presented can also be applied to discover other nonlinear materials at any desired regime, or to improve the performance of existing ones.”
The researchers were caught off guard by STO’s performance. In lab tests conducted at 5 degrees Kelvin (-450 F), they noted non-linearities that were some 20 times greater than the best-known nonlinear optical material, lithium niobate, and almost triple that of the previously best-performing cryogenic material, barium titanate. In further experiments, the researchers used their knowledge of what ingredients are desired for optimal performance to substitute oxygen isotopes into the crystal. This nudged STO toward a key threshold known as quantum criticality, with results that were even greater still.
“By adding just two neutrons to exactly 33 percent of the oxygen atoms in the material, the resulting tunability increased by a factor of four,” Anderson noted. “We precisely tuned our recipe to get the best possible performance.”
Next steps
STO has other practical attributes that should be attractive to engineers, the team said. It can be synthesized. It can be modified structurally to fine-tune its properties, as with the oxygen isotopes. And it can be processed using conventional fabrication equipment, all at the wafer scale. All these characteristics suggest great potential for wider adoption of STO in cryogenic quantum applications, such as switches for lasers that allow quantum computers to transmit or manipulate data.
Vuckovic noted that the study was funded in part by industry – Samsung and the quantum computing team at Google, who are searching for just such new materials for devices to propel their efforts. She and the team are now turning their sights to realizing new cryogenic devices based on strontium titanate.
“We found this material on the shelf. We used it and it was amazing. We understood why it was good. Then – the cherry on the top – we knew how to do better, added that special sauce, and we made the world’s best material for these applications,” Anderson said. “It’s a great story.”
Reference: “Quantum critical electro-optic and piezo-electric nonlinearities” by Christopher P. Anderson, Giovanni Scuri, Aaron Chan, Sungjun Eun, Alexander D. White, Geun Ho Ahn, Christine Jilly, Amir Safavi-Naeini, Kasper Van Gasse, Lu Li and Jelena Vučković, 23 October 2025, Science.
DOI: 10.1126/science.adx8657
In addition to the funding provided by Samsung Electronics and Google, the study was supported by a Vannevar Bush Faculty Fellowship from the U.S. Department of Defense, and by the Department of Energy under the Q-NEXT program.
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3 Comments
You Made the World’s Best Material.
NO.
Based on the Topological Vortex Theory (TVT) , materials science knows no bounds. There is no best, only better. Don’t be fooled by pseudo scientific publications.
When we pursue the ultimate truth of all things, the space in which our bodies and all things exist may itself be the final and deepest puzzle we need to explore. This is not only the pursuit of physics, but also the most magnificent exploration of the origin of the universe by human reason.
Based on the Topological Vortex Theory (TVT), space is an uniformly incompressible physical entity. Space-time vortices are the products of topological phase transitions of the tipping points in space, are the point defects in spacetime. Point defects do not only impact the thermodynamic properties, but are also central to kinetic processes. They create all things and shape the world through spin and self-organization.
In today’s physics, some so-called peer-reviewed journals—including Physical Review Letters, Nature, Science, and others—stubbornly insist on and promote the following:
1. Even though θ and τ particles exhibit differences in experiments, physics can claim they are the same particle. This is science.
2. Even though topological vortices and antivortices have identical structures and opposite rotational directions, physics can define their structures and directions as entirely different. This is science.
3. Even though two sets of cobalt-60 rotate in opposite directions and experiments reveal asymmetry, physics can still define them as mirror images of each other. This is science.
4. Even though vortex structures are ubiquitous—from cosmic accretion disks to particle spins—physics must insist that vortex structures do not exist and require verification. Only the particles that like God, Demonic, or Angelic are the most fundamental structures of the universe. This is science.
5. Even though everything occupies space and maintains its existence in time, physics must still debate and insist on whether space exists and whether time is a figment of the human mind. This is science.
6. Even though space, with its non-stick, incompressible, and isotropic characteristics, provides a solid foundation for the development of physics, physics must still insist that the ideal fluid properties of space do not exist. This is science.
and go on.
Is this the counterintuitive science they widely promote?
What are the shames?
What are the corruption, dirtiness, and ugliness?
Under the topological vortex architecture, it is highly challenging for even two hydrogen atoms or two quarks to be perfectly symmetrical, let alone counter-rotating two sets of cobalt-60. Contemporary physics and so-called peer-reviewed publications (including Physical Review Letters, Science, Nature, etc.) stubbornly believe that two sets of counter rotating cobalt-60 are two mirror images of each other, constructing a more shocking pseudoscientific theoretical framework in the history of science than the “geocentric model”. This pseudo scientific framework and system have seriously hindered scientific progress and social development.
For nearly a century, physics has been manipulated by this pseudo scientific theoretical system and the interest groups behind it, wasting a lot of manpower, funds, and time. A large amount of pseudo scientific research has been conducted, and countless pseudo scientific papers have been published, causing serious negative impacts on scientific and social progress, as well as humanistic development.
Complexity does not necessarily mean that there is no logical and architectural framework to follow. Mathematics is the language and tool that reveals the motion of spacetime, rather than the motion itself. Although the physical form of spacetime vortices is extremely simple, their interaction patterns are highly complex, and we must develop more and richer mathematical languages to describe and understand them.
The development of the Topological Vortex Theory (TVT) reflects a progression from concrete physical phenomena to abstract mathematical modeling and, ultimately, to interdisciplinary unification.
——Excerpted from https://t.pineal.cn/blogs/4569/An-Overview-of-the-Development-of-Topological-Vortex-Theory-TVT.