Imperial College London
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ProfessorJohannesLischner

Faculty of Engineering, Department of Materials

Professor of Theory and Simulation of Materials
 
 
 
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Contact

 

+44 (0)20 7594 9949j.lischner

 
 
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Location

 

342Bessemer BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Stepanov:2020:10.1038/s41586-020-2459-6,
author = {Stepanov, P and Das, I and Lu, X and Fahimniya, A and Watanabe, K and Taniguchi, T and Koppens, FHL and Lischner, J and Levitov, L and Efetov, DK},
doi = {10.1038/s41586-020-2459-6},
journal = {Nature},
pages = {375--378},
title = {Untying the insulating and superconducting orders in magic-angle graphene},
url = {http://dx.doi.org/10.1038/s41586-020-2459-6},
volume = {583},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The coexistence of superconducting and correlated insulating states in magic-angle twisted bilayer graphene1-11 prompts fascinating questions about their relationship. Independent control of the microscopic mechanisms that govern these phases could help uncover their individual roles and shed light on their intricate interplay. Here we report on direct tuning of electronic interactions in this system by changing the separation distance between the graphene and a metallic screening layer12,13. We observe quenching of correlated insulators in devices with screening layer separations that are smaller than the typical Wannier orbital size of 15 nanometres and with twist angles that deviate slightly from the magic angle of 1.10 ± 0.05 degrees. Upon extinction of the insulating orders, the vacated phase space is taken over by superconducting domes that feature critical temperatures comparable to those in devices with strong insulators. In addition, we find that insulators at half-filling can reappear in small out-of-plane magnetic fields of 0.4 tesla, giving rise to quantized Hall states with a Chern number of 2. Our study suggests re-examination of the often-assumed 'parent-and-child' relation between the insulating and superconducting phases in moiré graphene, and suggests a way of directly probing the microscopic mechanisms of superconductivity in strongly correlated systems.
AU  - Stepanov,P
AU  - Das,I
AU  - Lu,X
AU  - Fahimniya,A
AU  - Watanabe,K
AU  - Taniguchi,T
AU  - Koppens,FHL
AU  - Lischner,J
AU  - Levitov,L
AU  - Efetov,DK
DO  - 10.1038/s41586-020-2459-6
EP  - 378
PY  - 2020///
SN  - 0028-0836
SP  - 375
TI  - Untying the insulating and superconducting orders in magic-angle graphene
T2  - Nature
UR  - http://dx.doi.org/10.1038/s41586-020-2459-6
UR  - https://www.ncbi.nlm.nih.gov/pubmed/32632215
UR  - http://hdl.handle.net/10044/1/80955
VL  - 583
ER  -
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