Quantum effects observed in collisions of hydrogen molecules with noble gas atoms

A research team led by Professor Christiane Koch, a quantum physicist at Freie Universität Berlin, has conducted a study on the behavior of hydrogen molecules during collisions with noble gas atoms like helium or neon. Their findings, published in the journal Science, involve a combination of simulations, experimental data collected at TU Dortmund University and the Weizmann Institute of Science, and theoretical calculations in the field of quantum physics.

The study reveals that collisions between hydrogen molecules and noble gas atoms affect the vibration and rotation of the molecules according to the laws of quantum mechanics. These insights have practical applications in various technological advancements such as mobile phones, televisions, satellites, and medical diagnostic technology.

The observed quantum effect in this study is referred to as a Feshbach resonance. It occurs when a hydrogen molecule and a noble gas atom briefly form a chemical bond upon collision and then separate again. However, despite the team’s highly detailed measurements and calculations for this relatively simple system, fully reconstructing the complete quantum mechanical characteristics of the hydrogen-noble gas collision remains a significant challenge. This difficulty arises from a fundamental aspect of quantum mechanics: measurements cannot escape the fundamental principles of classical physics. Thus, researchers find themselves in a dilemma where certain phenomena of quantum mechanics can be mathematically described in abstract terms but require concepts from classical physics for a complete understanding.

Quantum effects, which involve behaviors beyond classical physics, manifest when atoms and molecules can no longer be adequately described solely by their position and speed. These effects include wave dispersion, such as wave interference (constructive or destructive layering of waves), as well as phenomena like entanglement, where spatially distant quantum objects exert immediate influence on each other.

Quantum effects are typically observed in the realm of very small objects like atoms and molecules, particularly when these entities experience minimal interaction with their environment. Achieving such conditions often requires extremely low temperatures approaching absolute zero (-273.15°C) or very short bursts of time. Under these circumstances, the particles exhibit only a limited number of quantum states, leading to orderly behavior.

At higher temperatures, particles possess a greater number of quantum states, and quantum effects tend to average out statistically across these states, effectively disappearing from observation. In this statistically predictable state, the system behaves more randomly and can be described using statistical methods. Until now, even the coldest atom-molecule collisions have demonstrated this statistically predictable behavior, making it challenging to establish a direct connection between experimental data and theoretical models regarding the interaction between atoms and molecules.

Overall, this research highlights the complex interplay between classical and quantum physics, providing valuable insights into the behavior of particles at the quantum level and their applications in various fields of technology.

Source: Freie Universität Berlin

Leave a Comment