Spin-Split Band Hybridization in Graphene Proximitized with α-RuCl₃ Nanosheets

Abstract

Proximity effects induced in the 2D Dirac material graphene potentially open access to novel and intriguing physical phenomena. Thus far, the coupling between graphene and ferromagnetic insulators has been experimentally established. However, only very little is known about graphene's interaction with antiferromagnetic insulators. Here, we report a low temperature study of the electronic properties of high quality van der Waals heterostructures composed of a single graphene layer proximitized with -RuCl 3 . The latter is known to become antiferromagnetically ordered below 10 K. Shubnikov de Haas oscillations in the longitudinal resistance together with Hall resistance measurements provide clear evidence for a band realignment that is accompanied by a transfer of electrons originally occupying the graphene's spin degenerate Dirac cones into -RuCl 3 band states with in-plane spin polarization. Left behind are holes in two separate Fermi pockets, only the dispersion of one of which is distorted near the Fermi energy due to spin selective hybridization with these spin polarized -RuCl 3 band states. This interpretation is supported by our DFT calculations. An unexpected damping of the quantum oscillations as well as a zero field resistance upturn close to the Néel temperature of -RuCl 3 suggests the onset of additional spin scattering due to spin fluctuations in the -RuCl 3 .

Charge-Transfer Plasmon Polaritons at Graphene/α-RuCl3 Interfaces

“… 35 Similarly, patterned α-RuCl 3 arrays should offer a superior route to creating the sharp periodic potentials needed to realize graphene photonic crystals in gate-tunable graphene/semiconductor architectures. 8 , 10 , 36 Concurrently, we have refined a procedure for probing the nanoscale optical response of 2D heterostructures across interfaces via the exploration of plasmon damping. This latter analysis hints at an enhanced electronic response in our doped interfacial α-RuCl 3 that needs to be verified with future direct measurements in the terahertz regime.…”

Electrical Probes of the Non-Abelian Spin Liquid in Kitaev Materials

“…[60,64], quantized thermal Hall conductance persists up to temperatures of roughly 5 K, suggesting a spin-liquid bulk gap of similar magnitude-an encouraging figure compared to the gap expected in most other candidate non-Abelian platforms [65]. Moreover, α-RuCl 3 affords a great deal of materials-science flexibility [66][67][68][69]: It is exfoliatable, amenable to nanofabrication, can be readily interfaced with other materials, etc.…”

Asymmetric modulation of Majorana excitation spectra and nonreciprocal thermal transport in the Kitaev spin liquid under a staggered magnetic field

“…Such a situation would be realized in a heterostructure composed of α-RuCl 3 and a honeycomb antiferromagnet. Note that van der Waals heterostructures of atomically thin α-RuCl 3 and graphene have been fabricated [36][37][38][39], which would be extended to the current situation. Besides, a superstructure of an ilmenite MnTiO 3 including IrO 6 honeycomb layers [40,41] could be such a platform, where the antiferromagnetic moment in MnTiO 3 can be regarded as a staggered internal magnetic field acting on the possible Kitaev spin liquid in the IrO 6 honeycomb layers [42][43][44].…”