Valley-contrasting physics in all-dielectric photonic crystals: Orbital angular momentum and topological propagation

The valley has been exploited as a binary degree of freedom to realize valley-selective Hall transport and circular dichroism in two-dimensional layered materials, in which valley-contrasting physics is indispensable in making the valley index an information carrier. In this Rapid Communication, we reveal valley-contrasting physics in all-dielectric valley photonic crystals. The link between the angular momentum of light and the valley state is discussed, and unidirectional excitation of the valley chiral bulk state is realized by sources carrying orbital angular momentum with proper chirality. Characterized by the nonzero valley Chern number, valley-dependent edge states and the resultant broadband robust transport is found in such an all-dielectric system. Our work has potential in the orbital angular momentum assisted light manipulation and the discovery of valley-protected topological states in nanophotonics and on-chip integration.

[1]  Gennady Shvets,et al.  Photonic topological insulators. , 2013, Nature materials.

[2]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[3]  J. Joannopoulos,et al.  Photonic crystals: putting a new twist on light , 1997, Nature.

[4]  Cheng-Cheng Liu,et al.  Valley-polarized quantum anomalous Hall effect in silicene. , 2013, Physical review letters.

[5]  A. Kis,et al.  Valley Zeeman e ect in elementary optical excitations of monolayerWSe 2 , 2015 .

[6]  F. Capasso,et al.  Polarization-Controlled Tunable Directional Coupling of Surface Plasmon Polaritons , 2013, Science.

[7]  M. Ablowitz,et al.  Unveiling pseudospin and angular momentum in photonic graphene , 2014, Nature Communications.

[8]  S. Raghu,et al.  Possible realization of directional optical waveguides in photonic crystals with broken time-reversal symmetry. , 2008, Physical review letters.

[9]  Alexander Szameit,et al.  Photonic Floquet Topological Insulators , 2013, CLEO 2013.

[10]  C. W. J. Beenakker,et al.  Valley filter and valley valve in graphene , 2007 .

[11]  J. Rarity,et al.  Polarization Engineering in Photonic Crystal Waveguides for Spin-Photon Entanglers. , 2014, Physical review letters.

[12]  Jin Dong Song,et al.  Deterministic photon-emitter coupling in chiral photonic circuits. , 2014, Nature nanotechnology.

[13]  Shuang Zhang,et al.  Pseudospin-induced chirality with staggered optical graphene , 2016, Light, science & applications.

[14]  P. L. McEuen,et al.  The valley Hall effect in MoS2 transistors , 2014, Science.

[15]  L. Chrostowski,et al.  Integrated optical Dirac physics via inversion symmetry breaking , 2016 .

[16]  Xiao Hu,et al.  Scheme for Achieving a Topological Photonic Crystal by Using Dielectric Material. , 2015, Physical review letters.

[17]  Johannes Courtial,et al.  Light’s Orbital Angular Momentum , 2004 .

[18]  E. Waks,et al.  Two-dimensionally confined topological edge states in photonic crystals , 2016, 1605.08822.

[19]  M. Padgett,et al.  Advances in optical angular momentum , 2008 .

[20]  Jianwen Dong,et al.  Manipulating pseudospin-polarized state of light in dispersion-immune photonic topological metacrystals , 2015 .

[21]  L. Levitov,et al.  Topological Valley Currents in Gapped Dirac Materials. , 2014, Physical review letters.

[22]  M. Babiker,et al.  The angular momentum of light , 2012 .

[23]  The Emergence of Dirac points in Photonic Crystals with Mirror Symmetry , 2014, Scientific reports.

[24]  A. Rauschenbeutel,et al.  Chiral nanophotonic waveguide interface based on spin-orbit interaction of light , 2014, Science.

[25]  Gennady Shvets,et al.  All-Si valley-Hall photonic topological insulator , 2016, 2016 Conference on Lasers and Electro-Optics (CLEO).

[26]  Wang Yao,et al.  Valley-dependent optoelectronics from inversion symmetry breaking , 2007, 0705.4683.

[27]  S. Skirlo,et al.  Multimode one-way waveguides of large Chern numbers. , 2014, Physical review letters.

[28]  Aaron M. Jones,et al.  Supplementary Materials Magnetic Control of Valley Pseudospin in Monolayer WSe2 , 2014, 1407.2645.

[29]  Wang Yao,et al.  Spin and pseudospins in layered transition metal dichalcogenides , 2014, Nature Physics.

[30]  M. Tahir,et al.  Valley polarized quantum Hall effect and topological insulator phase transitions in silicene , 2012, Scientific Reports.

[31]  Jakob S. Jensen,et al.  Topology optimization and fabrication of photonic crystal structures. , 2004, Optics express.

[32]  Yuan Wang,et al.  Valley photonic crystals for control of spin and topology. , 2017, Nature materials.

[33]  C. Chan,et al.  One-way edge mode in a magneto-optical honeycomb photonic crystal , 2009 .

[34]  T. Baba,et al.  Observation of polarization singularities at the nanoscale , 2009, CLEO/Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference.

[35]  Siyuan Yu,et al.  Integrated Compact Optical Vortex Beam Emitters , 2012, Science.

[36]  Wang Yao,et al.  Valley-contrasting physics in graphene: magnetic moment and topological transport. , 2007, Physical review letters.

[37]  Steven G. Louie,et al.  Probing excitonic dark states in single-layer tungsten disulphide , 2014, Nature.

[38]  C. T. Chan,et al.  Experimental realization of photonic topological insulator in a uniaxial metacrystal waveguide. , 2014, Nature communications.