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arXiv · 1611.04518

Exploring Novel Quantum Criticality in Strained Graphene

S. Arya·M. S. Laad·S. R. Hassan
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Abstract

Strain tuning is increasingly being recognized as a clean tuning parameter to induce novel behavior in quantum matter. Motivated by the possibility of straining graphene up to $20$ percent, we investigate novel quantum criticality due to interplay between strain-induced anisotropic band structure and critical antiferromagnetic spin fluctuations (AFSF) in this setting. We detail how this interplay drives $(i)$ a quantum phase transition (QPT) between the Dirac-semimetal-incoherent pseudogapped metal-correlated insulator as a function of strain ($ε$), and $(ii)$ critical AFSF-driven divergent nematic susceptibility near critical strain ($ε_{c}$) manifesting as critical singularities in magneto-thermal expansion and Grüneisen co-efficients. The correlated band insulator at large strain affords realization of a two-dimensional dimerized spin-singlet state due to this interplay, and we argue how doping such an insulator can lead to a spin-charge separated metal, leading to anomalous metallicity and possible unconventional superconductivity. On a wider front, our work serves to illustrate the range of novel states realizable by strain-tuning quantum materials.

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S. Arya, M. S. Laad, S. R. Hassan. 2016-11-14. Exploring Novel Quantum Criticality in Strained Graphene. https://doi.org/10.1103/physrevb.96.085126

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