Nature’s most captivating aspects often lie in its imperfections. This notion holds especially true in the realm of quantum physics, where even minute flaws can have profound effects on particle behavior and interactions.
In a recent publication in Nature Communications, Chong Zu, an assistant professor of physics at Washington University in St. Louis, and his team have been exploring novel methods to harness the quantum potential of defects within otherwise flawless crystals.
Supported in part by the Center for Quantum Leaps, a strategic initiative of the Arts & Sciences program, their research aims to apply quantum insights and technologies to diverse fields such as physics, biomedical sciences, life sciences, and drug discovery.
Zu’s laboratory focuses on atomic imperfections in boron nitride, a material that forms ultra-thin two-dimensional sheets. While boron nitride is typically uniform and unchanging, occasional vacancies may occur when a boron atom is missing, creating minuscule gaps. Although these gaps can arise naturally, Zu and his team, including graduate student Ruotian (Reginald) Gong, accelerated the process by bombarding microscopic flakes of the material with helium atoms—tiny atomic bullets that randomly dislodge boron atoms.
These resulting gaps possess significant quantum potential. They naturally fill with highly sensitive electrons, which respond to their environment. For instance, slight variations in magnetic fields and temperature can alter the spin and energy state of these electrons. Such sensitivity makes them valuable as quantum sensors. In their latest study, Zu, Gong, and their colleagues demonstrated, for the first time, that these electrons also react to changes in electric fields, expanding the potential range of applications.
Since these sensors are embedded within a thin, stable matrix of boron nitride, they could theoretically be employed in various substances, from geological to biological samples. In contrast, other types of sensors typically necessitate a vacuum environment chilled to temperatures close to absolute zero.
Zu emphasized the advantages of room temperature boron nitride sensors, stating, “You could never put something that cold next to a living cell.” Furthermore, these sensors hold potential for utilization in basic simulation experiments, enabling the study of quantum particle interactions. While physicists often rely on computer simulations to predict particle behavior, the complexity of these systems limits the speed of even the most powerful computers.
“Instead of attempting to construct the systems on a computer, you can simply create the exact system you wish to study and observe the interactions,” Zu explained.