Spin Chern Pumping from the Bulk of Two-Dimensional Topological Insulators

Abstract

Topological insulators (TIs) are a new quantum state of matter discovered recently, which are characterized by unconventional bulk topological invariants. Proposals for practical applications of the TIs are mostly based upon their metallic surface or edge states. Here, we report the theoretical discovery of a bulk quantum pumping effect in a two-dimensional TI electrically modulated in adiabatic cycles. In each cycle, an amount of spin proportional to the sample width can be pumped into a nonmagnetic electrode, which is attributed to nonzero spin Chern numbers $C_{\pm }$. Moreover, by using a half-metallic electrode, universal quantized charge pumping conductivities $-C_{\pm }{e}^2/h$ can be measured. This discovery paves the way for direct investigation of the robust topological properties of the TIs.

11 pages, 4 figures

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Cited by in corpus (7)

• Effects of Dephasing on Quantum Adiabatic Pumping with Nonequilibrium Initial States
• Non-adiabatic topological spin pumping
• Quantized charge-pumping in higher-order topological insulators
• Realization of valley-spin polarized current via parametric pump in monolayer $\mathrm{Mo}{\mathrm{S}}_2$
• Topological Spin and Valley Pumping in Silicene
• Fractional quantization of charge and spin in topological quantum pumps
• Analytical theory and possible detection of the $ac$ quantum spin Hall effect