Experimental Observation of Repulsively Bound Magnons in Antiferromagnetic Spin Chains

Belangrijkste concepten

Experimental observation of repulsively bound three-magnon states and bound magnon pairs in the Ising-like chain antiferromagnet BaCo2V2O8, demonstrating the existence of stable composite objects formed by repulsive interactions in condensed matter systems.

Samenvatting

The article presents experimental evidence for the formation of repulsively bound magnon states in the Ising-like chain antiferromagnet BaCo2V2O8. Traditionally, composite objects stabilized by repulsive forces were thought to be theoretically possible but unlikely to occur in natural systems due to their fragility. However, the authors show that in the presence of large transverse magnetic fields, below the quantum critical point, the system exhibits spectroscopic signatures of repulsively bound three-magnon states and bound magnon pairs.

The authors compare their experimental results to theoretical models for the Heisenberg-Ising chain antiferromagnet, a well-studied quantum many-body system. They find that these high-energy, repulsively bound magnon states are well-separated from continua, exhibit notable dynamical responses, and are sufficiently long-lived to be identified despite dissipation. The authors suggest that the transport properties in spin chains can be altered by the presence of these magnon bound states, and envision potential applications in magnonic-based quantum information processing technologies.

Statistieken

The Ising-like chain antiferromagnet BaCo2V2O8 was used in the experiments.
Large transverse magnetic fields were applied to the system, below the quantum critical point.

Citaten

"Stable composite objects, such as hadrons, nuclei, atoms, molecules and superconducting pairs, formed by attractive forces are ubiquitous in nature. By contrast, composite objects stabilized by means of repulsive forces were long thought to be theoretical constructions owing to their fragility in naturally occurring systems."
"Our experimental results show that these high-energy, repulsively bound magnon states are well separated from continua, exhibit notable dynamical responses and, despite dissipation, are sufficiently long-lived to be identified."

Belangrijkste Inzichten Gedestilleerd Uit

Experimental observation of repulsively bound magnons - Nature

by Zhe Wang,Cat... om www.nature.com 06-26-2024

https://www.nature.com/articles/s41586-024-07599-3

Diepere vragen

What are the specific mechanisms that stabilize the repulsively bound magnon states in the Ising-like antiferromagnet, and how do they differ from the stabilization of composite objects formed by attractive forces?

In the Ising-like chain antiferromagnet BaCo2V2O8, the repulsively bound magnon states are stabilized by the strong repulsive interactions between magnons. These repulsive interactions lead to the formation of bound magnon pairs and three-magnon states. Unlike composite objects formed by attractive forces, where stability arises from the energy minimization due to attractive interactions, repulsively bound magnon states are stabilized by the balance between repulsive forces and quantum fluctuations. This delicate balance allows for the existence of these high-energy states in the system.

How might the presence of repulsively bound magnon states affect the transport and other properties of spin chains, and what are the potential implications for magnonic-based quantum information processing?

The presence of repulsively bound magnon states in spin chains can significantly impact their transport properties. These bound states can alter the dynamics of magnon transport, leading to novel phenomena in spin chains. For instance, the interaction between magnons in repulsively bound states can modify the magnon dispersion relation and affect the thermal and electrical conductivity of the system. In terms of magnonic-based quantum information processing, the existence of these bound states opens up possibilities for utilizing them as resources for quantum information storage and manipulation. By controlling and manipulating these repulsively bound magnon states, new avenues for developing magnonics-based quantum technologies could be explored.

Given the successful observation of repulsively bound magnon states in this system, are there other types of condensed matter systems where similar repulsively bound composite objects might be found, and what would be the significance of such discoveries?

The successful observation of repulsively bound magnon states in the Ising-like chain antiferromagnet suggests that similar phenomena could potentially exist in other condensed matter systems with strong repulsive interactions. Systems with frustrated magnetic interactions, such as spin liquids or exotic magnetic materials, could harbor repulsively bound composite objects like magnon pairs or higher-order bound states. Discovering and characterizing these repulsively bound states in different systems could provide valuable insights into the interplay between repulsive interactions, quantum fluctuations, and emergent phenomena in quantum magnets. Furthermore, understanding the stability and properties of repulsively bound composite objects in various condensed matter systems could pave the way for the design of novel quantum materials and devices with tailored functionalities.