Valley and pseudospin-valley topologically protected edge states in symmetric pillared phononic crystals

Autor:	Wang, Wei, Bonello, Bernard, Djafari-Rouhani, Bahram, Pennec, Yan
Rok vydání:	2019
Předmět:	Physics - Applied Physics Condensed Matter - Mesoscale and Nanoscale Physics
Zdroj:	Phys. Rev. B 100, 140101 (2019)
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevB.100.140101
Popis:	We present a symmetric double-sided pillared phononic crystals (PPnCs) that can emulate both quantum spin Hall effect (QSHE) and quantum valley Hall effect (QVHE) by solely imposing different geometric perturbations. Indeed, the Dirac cones can occur in the low (deep subwavelength) and high frequency regime by judiciously turning the parameters of the attached pillars and even a double Dirac cone can be achieved. We realize the valley-protected, the pseudospin-protected or the pseudospin-valley coupled edge states with the proposed platform. Besides, we show a variety of refraction phenomena (positive, negative and evanescent) of the valley-polarized edge state at the zigzag termination when emulating QVHE. Further, we illustrate the valley-dependent feature of the pseudospin-valley coupled edge state and demonstrate the valley based splitting of the pseudospin-protected edge states in a Y-junction wave guide. Comment: 4 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1905.04936 Zobrazit plný text záznamu View this record from Arxiv