First evidence of ‘quantum superchemistry’ in the laboratory
Researchers from the University of Chicago have revealed the initial proof of ‘quantum superchemistry.’
This occurrence involves particles within an identical quantum state engaging in synchronised accelerated reactions. Although this effect had been foreseen, it had never been experimentally witnessed before.
The discoveries, documented on July 24 in the journal Nature Physics, open the door to a new field. Researchers are captivated by the prospect of ‘quantum-enhanced’ chemical reactions, which could hold significance in quantum chemistry, quantum computing, and various technological domains. Additionally, these findings could contribute to a deeper comprehension of the fundamental principles governing the universe.
“What we saw lined up with the theoretical predictions,” said Cheng Chin, a professor of physics and member of the James Franck Institute and Enrico Fermi Institute, whose lab conducted the research. “This has been a scientific goal for 20 years, so it’s a very exciting era.”
Chin's laboratory specialises in manipulating particles at extremely low temperatures. In proximity to absolute zero, these particles have the potential to synchronise into a single quantum state, a condition that grants them the capacity to showcase extraordinary capabilities and behaviours.
Theorists had hypothesised that a collective assembly of atoms and molecules existing within the same quantum state would exhibit distinct behaviour in the course of chemical reactions. However, the challenges associated with orchestrating the necessary experiment had prevented any observational confirmation of this phenomenon.
Chin's team possesses expertise in guiding atoms into quantum states; however, molecules, being larger and considerably more intricate than atoms, presented a more intricate challenge. As a result, the group had to devise innovative methodologies to effectively manage and manipulate these molecules.
During the experiments, the researchers employed a cooling process to lower the temperature of cesium atoms and encouraged them to enter the same quantum state. Subsequently, they observed the reaction of these atoms as they combined to create molecules.
In traditional chemistry, individual atoms collide, and each collision carries a probability of forming a molecule. However, according to the principles of quantum mechanics, atoms in a shared quantum state engage in collective actions, deviating from the conventional behaviour.
“You are no longer treating a chemical reaction as a collision between independent particles, but as a collective process,” explained Chin. “All of them are reacting together, as a whole.”
A notable outcome of this phenomenon is that the reaction occurs at an accelerated pace compared to standard conditions. Remarkably, the presence of more atoms within the system leads to an even swifter occurrence of the reaction.
Another significant outcome is that the resultant molecules all possess the same molecular state. Chin clarified that molecules existing in distinct states can exhibit varied physical and chemical characteristics. However, there are situations where generating a set of molecules in a particular state is desirable. In conventional chemistry, this outcome is uncertain. "But through this method, you can guide the molecules to adopt an identical state," he remarked.
Shu Nagata, a co-author of the study and a graduate student, mentioned that they detected indications indicating that the reaction predominantly occurred as a three-body interaction rather than a two-body interaction. In this context, three atoms would engage in collisions, resulting in two atoms forming a molecule while the third atom remained uncombined. Despite not directly participating in the formation of the molecule, the third atom still played a role in influencing the reaction.
The researchers hope for this breakthrough to mark the commencement of a novel era in their field. While the current experiment was conducted using basic, two-atom molecules, their intention is to progressively advance towards managing larger and intricately structured molecules in their future endeavours.
“How far we can push our understanding and our knowledge of quantum engineering, into more complicated molecules, is a major research direction in this scientific community,” said Chin.
Certain experts in the field have envisaged the utilisation of molecules as qubits in quantum computers or for quantum information processing purposes. Concurrently, other researchers are investigating molecules as potential avenues to achieve heightened precision in measuring fundamental laws and interactions. This could encompass endeavours like scrutinising foundational principles of the universe, including concepts such as symmetry violation.