The physics of graphene can be strongly enriched and manipulated by harvesting the large amount of possibilities of proximity effects with magnetic insulators, strong SOC materials (TMDC, topological insulators, etc.). Simultaneously, the presence of extra degrees of freedom (sublattice pseudospin, valley isospin) points towards new directions for information processing [1,2], extending the playground to valleytronics, multifunctional electronic devices or novel quantum computing paradigms harnessing all these degrees of freedom in combination with electromagnetic fields or other external fields (strain, chemical functionalization) [3,4]. 

Here I will present some foundations of spin transport for Dirac fermions propagating in supported graphene devices or interfaced with strong SOC materials. The role of entanglement with “valley and sublattice pseudospins” in tailoring the spin dephasing and relaxation mechanisms will be explained as well as the impact of strong SOC proximity effects on spin lifetime anisotropy, weak antilocalization and Spin Hall effect [4-8]. I will also refute recent claims concerning the formation of the valley Hall effect in graphene/hBN heterostructures which relate measured giant non-local resistance with Berry curvature-induced bulk valley currents [9]. Such analysis is fundamentally flawed, whereas the understanding of non-local transport properties requires advanced and realistic quantum transport calculations (see recent advances published in [10]).

[1] S. Roche et al. 2D Materials 2, 030202 (2015).

[2] D.V. Tuan et al. Nature Physics 10, 857 (2014).

[3] D.V. Tuan & S. Roche, Phys. Rev. Lett. 116, 106601 (2016).

[4] A.W. Cummings, J. H. García, J. Fabian and S. Roche, Phys. Rev. Lett. 119, 206601 (2016).

[5] J.H. García, A.W. Cummings, S. Roche, Nano Lett. 17 (8), 5078–5083 (2017).

[6] K. Song, D. Soriano, A.W. Cummings, R. Robles, P. Ordejón & S. Roche, Nano lett. 18 (3), 2033 (2018).

[7] J.H. García,  M. Vila,  A.W. Cummings & S. Roche, Chem. Soc. Rev. 47, 3359-3379 (2018).

[8] D. Khokhriakov, A.W. Cummings, M. Vila, B. Karpiak, A. Dankert,

S. Roche & S.P. Dash, Science Advances (in press)

[9] A. Cresti et al. Riv. Nuovo Cimento 39, 587 (2018).

[10] J. M. Marmolejo-Tejada et al., arXiv:1706.09361; J. Phys. Materials (in press).

The physics of graphene can be strongly enriched and manipulated by harvesting the large amount of possibilities of proximity effects with magnetic insulators, strong SOC materials (TMDC, topological insulators, etc.). Simultaneously, the presence of extra degrees of freedom (sublattice pseudospin, valley isospin) points towards new directions for information processing [1,2], extending the playground to valleytronics, multifunctional electronic devices or novel quantum computing paradigms harnessing all these degrees of freedom in combination with electromagnetic fields or other external fields (strain, chemical functionalization) [3,4]. 

Here I will present some foundations of spin transport for Dirac fermions propagating in supported graphene devices or interfaced with strong SOC materials. The role of entanglement with “valley and sublattice pseudospins” in tailoring the spin dephasing and relaxation mechanisms will be explained as well as the impact of strong SOC proximity effects on spin lifetime anisotropy, weak antilocalization and Spin Hall effect [4-8]. I will also refute recent claims concerning the formation of the valley Hall effect in graphene/hBN heterostructures which relate measured giant non-local resistance with Berry curvature-induced bulk valley currents [9]. Such analysis is fundamentally flawed, whereas the understanding of non-local transport properties requires advanced and realistic quantum transport calculations (see recent advances published in [10]).

[1] S. Roche et al. 2D Materials 2, 030202 (2015).

[2] D.V. Tuan et al. Nature Physics 10, 857 (2014).

[3] D.V. Tuan & S. Roche, Phys. Rev. Lett. 116, 106601 (2016).

[4] A.W. Cummings, J. H. García, J. Fabian and S. Roche, Phys. Rev. Lett. 119, 206601 (2016).

[5] J.H. García, A.W. Cummings, S. Roche, Nano Lett. 17 (8), 5078–5083 (2017).

[6] K. Song, D. Soriano, A.W. Cummings, R. Robles, P. Ordejón & S. Roche, Nano lett. 18 (3), 2033 (2018).

[7] J.H. García,  M. Vila,  A.W. Cummings & S. Roche, Chem. Soc. Rev. 47, 3359-3379 (2018).

[8] D. Khokhriakov, A.W. Cummings, M. Vila, B. Karpiak, A. Dankert,

S. Roche & S.P. Dash, Science Advances (in press)

[9] A. Cresti et al. Riv. Nuovo Cimento 39, 587 (2018).

[10] J. M. Marmolejo-Tejada et al., arXiv:1706.09361; J. Phys. Materials (in press).