Physicists have observed a new quantum effect in topological insulators for the first time at room temperature. Princeton University researchers found that a topological insulator made of bismuth and bromine exhibits special quantum behavior that is usually seen only under high pressure or extreme experimental conditions near absolute zero.
This discovery opens up a series of new possibilities for the development of efficient quantum technologies, such as spin-based energy-efficient electronics. The study was published as the cover article in the October issue of the magazine Nature Materials.
Although scientists have been using the topological insulator for the past decade to prove the quantum effect , this experiment is the first time these effects have been observed at room temperature. Induction and observation of quantum state in topological insulators usually requires a temperature near absolute zero, i.e., negative 459 degrees Fahrenheit (or -273 degrees Celsius).
This discovery opens up new possibilities for the development of efficient quantum technologies, such as spin-based electronics, which has the potential to replace many current electronic systems with higher energy efficiency.
: Zahid Hasan said: "Whether from the perspective of basic physics or looking for potential applications in the next generation of quantum engineering and nanotechnology, the new topological properties of matter have become one of the most popular treasures in modern physics. This research is thanks to the progress of several innovative experiments in our Princeton laboratory."
topological insulator is the main device component used to study the mystery of quantum topology. This is a unique device that acts as an insulator inside it, meaning that the electrons inside cannot move freely and therefore do not conduct electricity. However, electrons at the edge of the device can move freely, meaning they are electrically conductive.
In addition, due to the special nature of the topology, electrons flowing along the edges are not hindered by any defects or deformations. The device has the potential to improve technology, but also the potential to deepen the understanding of the matter itself by probing the characteristics of the sub-electronics.
Hassan said: "People are interested in topological materials and people often talk about their huge potential in practical applications. But these applications may still not be able to achieve until some macroscopic quantum topological effects can be exhibited at room temperature."
This is mainly because what physicists call " thermal noise " (defined as rising temperature, causing atom to start vibrating violently) needs to be created in harsh environments or high temperatures. This behavior can destroy subtle quantum systems, thus breaking down quantum states. Especially in topological insulators, these higher temperatures can cause electrons on the surface of the insulator to invade the interior or "blocks" of the insulator and cause the electrons there to also begin to conduct, diluting or destroying special quantum effects.
The solution to this problem is to place such experiments at unusually cold temperatures, usually at or near absolute zero. At these incredibly low temperatures, atoms and subatomic particles stop vibrating, making them easier to manipulate. But for many applications, it is impractical to create and maintain ultra-cold environments. It is costly, large in size, and consumes a lot of energy.
However, however, Hassan and his team have developed an innovative way to bypass this problem. Based on their experience in topological materials and working with many collaborators, they have made a new topological insulator made from bismuth bromide (chemical formula α-Bi4Br4), an inorganic crystalline compound that is sometimes used in water treatment and chemical analysis. "We found that this quantum state occurs without huge pressure or ultra-high magnetic fields, making these materials easier to use in developing next-generation quantum technologies," said Nana Shumiya. She is a PhD at Princeton University, a postdoctoral research assistant in electrical and computer engineering, and is one of the three co-first authors of the paper. "I believe our discovery will significantly advance the quantum frontier," said Shumiya.
