⚛️ A simple chemical tweak makes quantum computers reliable and efficient

The key to building reliable quantum computers may lie in a simple chemical recipe adjustment. Researchers have found that a slight change in the ratio between two elements is enough to push a material into exotic quantum states. This method thus offers a new approach to mastering these phenomena.

Quantum computers promise to solve problems beyond the reach of classical machines. However, their development is hampered by the difficulty of maintaining stable quantum information, often disturbed by environmental noise. These machines therefore require highly precise components to operate with an error rate low enough to allow usable computation, making them particularly expensive.


Faced with this obstacle, scientists are interested in a particular category of materials: topological superconductors. The latter have 'protected' quantum properties, likely to serve as a shield against perturbations and preserve data reliably. However, their practical realization remains delicate, as it requires very specific conditions.

A team from the University of Chicago and West Virginia University has developed a simpler strategy to obtain these properties. By growing extremely thin films of a compound based on iron, tellurium, and selenium, they can alter the ratio between tellurium and selenium. This alteration influences how electrons interact collectively, allowing a 'tuning' of the material towards the desired state.

The work, published in Nature Communications, indicates that these electron interactions play a determining role. When they are too strong, the electrons freeze; too weak, the topological properties vanish. But at an optimal level, the material becomes a topological superconductor.

Haoran Lin, a graduate student, compares this effect to a potentiometer that can be turned to reach the ideal regime.


This approach based on thin films, easier to control and integrate into devices than bulk crystals, offers other advantages. These materials operate at higher temperatures than some alternatives, around 13 Kelvin, which simplifies their cooling with standard liquid helium. Moreover, their format is ideal for manufacturing electronic components, paving the way for concrete applications.

Now, several research groups are collaborating to shape these films and manufacture quantum components. Shuolong Yang, an associate professor, sees it as an effective tool for designing more robust systems, which could accelerate the development and deployment of quantum computers.