Graphite’s Quantum Puzzle. A major breakthrough has occurred in the understanding of graphite, an age-old material. By leveraging van der Waals technology and twistronics, scientists have uncovered new physics within the structure of graphite, specifically a 2.5-dimensional interaction between surface and bulk states. This discovery leads to newfound avenues in controlling electronic characteristics in both 2D and 3D materials. Credit goes to Prof. Jun Yin (a co-author of the study).
The National Graphene Institute at The University of Manchester has revealed previously unknown physics in graphite by employing twistronics, resulting in a 2.5-dimensional blending of surface and bulk states. This work opens new doors for controlling electronic properties across 2D and 3D substances.
Investigators at the National Graphene Institute (NGI) of The University of Manchester have revisited graphite, one of Earth’s oldest materials, and stumbled upon new physics that has remained hidden for many years.
Table of Contents
The Intricacy of Graphite
Despite its seemingly simple honeycomb arrangement of carbon atoms, natural graphite is far more complex than it appears. Its complexity comes from the various ways these atomic layers align, leading to different forms of graphite. The most common natural form involves hexagonal stacking, but the graphite’s repetitive structure is disrupted at the surface, creating so-called ‘surface states.’ The ability to modify these surface states in graphite was previously poorly understood.
Breakthroughs via Twistronics
Two pioneering areas in 2D materials research, van der Waals technology and twistronics (aligning two 2D crystals at a twisted angle to significantly alter the properties of the resulting structure due to the moiré pattern created), are now being employed by NGI researchers, headed by Prof. Artem Mishchenko. They are using the moiré pattern to manipulate graphite’s surface states, unveiling extraordinary new aspects of graphite’s physics.
Specifically, Prof. Mishchenko has extended the twistronics approach to three-dimensional graphite. He discovered that the moiré potential influences not only the graphite’s surface states but the entire electronic spectrum of the graphite crystal, much like the famous tale of The Princess and The Pea where the princess felt the pea through multiple layers.
Observations and What They Mean
Recently published in the journal Nature, the research delved into the effects of moiré patterns in bulk hexagonal graphite aligned with hexagonal boron nitride. The most captivating finding is a 2.5-dimensional amalgamation of surface and bulk states in graphite, resulting in a new form of fractal quantum Hall effect – the 2.5D Hofstadter’s butterfly.
Prof. Artem Mishchenko and Ciaran Mullan, leading figures in the study, expressed the excitement and potential of this work, noting that it heralds new ways to control electronic properties in both 2D and 3D materials.
Concluding Remarks
Prof. Vladimir Fal’ko, head of the National Graphene Institute, emphasized that the unprecedented 2.5D quantum Hall effect in graphite represents an interaction between two well-known quantum physics phenomena. This leads to a completely new form of quantum effect.
The team is now focusing on further exploration of graphite, aiming to uncover more about this unexpectedly intriguing material.
Reference: “Mixing of moiré-surface and bulk states in graphite” by Ciaran Mullan et al., 19 July 2023, Nature.
DOI: 10.1038/s41586-023-06264-5
Frequently Asked Questions (FAQs) about fokus keyword: graphite
What is the significant discovery made in graphite?
Researchers have uncovered new physics within the structure of graphite, specifically a 2.5-dimensional interaction between surface and bulk states. This leads to the observation of a new type of fractal quantum Hall effect known as the 2.5D Hofstadter’s butterfly.
How was this discovery in graphite achieved?
The discovery was achieved by leveraging van der Waals technology and a method known as twistronics, where two 2D crystals are aligned at a twist angle to modify the properties of the resulting structure.
What is twistronics, and how does it relate to graphite?
Twistronics is a technique that involves stacking two 2D crystals at a specific twist angle to tune the properties of the resulting structure due to the moiré pattern formed at their interface. In the case of graphite, twistronics was employed to manipulate its surface states, revealing new physics.
What are the implications of this discovery in graphite?
The discovery opens up new possibilities for controlling electronic properties in both 2D and 3D materials, enhancing understanding of graphite’s structure and potentially leading to innovative applications in various fields.
Who led the research on the new physics in graphite?
The research was led by the team of NGI (National Graphene Institute) researchers at The University of Manchester, guided by Prof. Artem Mishchenko.
What is the unusual 2.5D quantum Hall effect in graphite?
The 2.5D quantum Hall effect in graphite is an interplay between two quantum physics textbook phenomena – Landau quantization in strong magnetic fields and quantum confinement. It manifests itself in a new type of fractal quantum Hall effect and is one of the key findings of this research.
Where can I find the published research on graphite’s new physics?
The research was published in the journal Nature under the title “Mixing of moiré-surface and bulk states in graphite” on 19 July 2023.
More about fokus keyword: graphite
- National Graphene Institute at The University of Manchester
- Nature Journal
- Explanation of Twistronics
- Information on Graphite
