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Sputter Growth and Characterization of Metamagnetic B2-ordered FeRh Epilayers
Published on: October 5, 2013
Two phase transitions induced by a magnetic field in graphite
Benoît Fauqué1, David LeBoeuf, Baptiste Vignolle
1LPEM (UPMC-CNRS), Ecole Supérieure de Physique et de Chimie Industrielles, 75005 Paris, France. benoit.fauque@espci.fr
Physical Review Letters
|July 16, 2013
Summary
Strong magnetic fields induce two new ordered states in graphite, revealing an energy gap in out-of-plane conductivity alongside unexpected in-plane metallicity. These findings challenge existing theories on electron gas instabilities.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Magnetism
Background:
- Three-dimensional electron gas (3DEG) systems confined to the lowest Landau level are theoretically prone to various instabilities.
- The charge density wave (CDW) transition in graphite under a strong magnetic field is the sole experimentally confirmed instance of such instabilities.
- Understanding these phenomena is crucial for advancing quantum materials and condensed matter physics.
Purpose of the Study:
- To investigate the electronic properties of graphite under extreme magnetic fields.
- To identify and characterize novel phase transitions and instabilities in a 2D electron system.
- To explore the coexistence of bulk energy gaps and in-plane metallicity.
Main Methods:
- Magnetoresistance measurements were conducted on graphite samples up to 80 Tesla (T).
- Analysis focused on identifying phase transitions and their associated changes in conductivity.
- Theoretical considerations of edge-state transport were used to interpret experimental observations.
Main Results:
- Two successive magnetic-field-induced phase transitions were observed in graphite.
- Each transition leads to a distinct ordered state within a specific magnetic field range.
- An energy gap formed in the out-of-plane conductivity, while in-plane conductivity remained metallic.
- This unusual coexistence suggests the influence of edge states.
Conclusions:
- The study establishes new experimentally observed ordered states in graphite under high magnetic fields.
- The findings indicate a complex interplay between bulk and edge electronic states in confined electron systems.
- This work provides new insights into electron gas instabilities and phase transitions in layered materials.
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