The Talbot effect for a surface plasmon polariton

We propose a quantum spin Talbot effect for an electron beam transmitted through a grating of magnetic nanostructures. Tunable periodic magnetic nanostructures can be used in conjunction with electron-beam illumination to create a spin polarized replica of the transversely periodic exit surface beam a Talbot length away, due to quantum interference. Experiments have been proposed to verify the effect in a two dimensional electron gas. This effect provides a new route to modulate electron spin distributions without a magnetic field. A quantum spin Talbot interferometer and transistor are proposed for spintronics applications.The ability to tune scalable semiconductor-based spintronics devices, based on the intrinsic spin of electrons to store and manipulate information, is both important and highly challenging for spin-based electronics since spin injection, spin accumulation and spin modulation of electrons are required [1][2][3][4][5]. Currently, manipulation of the spin during transport between injector and detector via spin precession and spin pumping can be accomplished [6], however, those methods have difficulty controlling spin distributions. By contrast, local tunability of spin distributions over nanometer scales is crucial for future solid state quantum computers based on electron spin [7]. Inspired by the progress in fabricating and controlling nanoscale magnetic structures [8], we propose a spin-dependent quantum Talbot effect for electron waves transmitted by a grating composed of magnetic nanostructures, to modulate the spin lattice pattern formed from a spin polarized replica of the structure upon propagation through a Talbot length period and adjustable by controlling the electron wavelength and magnetic nanostructures' period. This leads to potential applications such as a quantum spin Talbot transistor and a quantum spin Talbot interferometer.The optical Talbot effect was discovered in 1836 [9], and later explained by Rayleigh as a natural consequence of Fresnel diffraction. He showed that the Talbot length Z T is given by Z T = 2a 2 λ [10], in the paraxial approximation a ≫ λ, where a is period of the grating and λ is the wavelength of the incident light. However, in a nonparaxial regime where λ a<2λ, the Talbot effect is also operative for nonevanescent components of the scattered beam [11]. This effect reveals the wave-nature of both radiation and matter wave fields, examples of the latter including atoms, electrons and plasmons [11-13, 15, 16, 31].In this Letter, we calculate a spin polarized nonparaxial Talbot effect for electron matter waves transmitted through a grating composed of magnetic nanostructures. We find that the spin asymmetry of the transmitted field varies with distance from the grating, creating an electron spin replica of the structure a Talbot length away, in a non-paraxial regime where λ a<2λ. This creates a tunable spin lattice in two-dimensional space, which is a powerful method to manipulate elec- tron spin distributions in solid state systems. We find that the quantum...

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“…For the paraxial approximation a≫λ, Eq. 4 approaches 2a 2 /λ, consistent with the literature [11,15,16]. The spin asymmetry distribution ( Fig.…”

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confidence: 90%

Proposal for electron quantum spin Talbot effect

2012

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“…In recent years, the analogue of the conventional Talbot effect has been investigated for surface plasmons (SPs), both theoretically [10][11][12][13] and experimentally [14][15][16], and plasmon Talbot carpets containing rich subwavelength hotspots are obtained. SPs are surface electromagnetic waves propagating along the interface of metal and dielectric, and are excited by the collective electron oscillations [17].…”

Section: Introductionmentioning

confidence: 99%

“…So far however, most research on plasmon Talbot effect focuses on one-dimensional (1D) periodical nanostructures, e.g. nanoholes [10,16], nanoslits [12,14], and nanoparticles [11,15], so that only two-dimensional (2D) plasmon Talbot revivals can be achieved. Li et al theoretically studied the three-dimensional (3D) plasmon Talbot effect of a nanolens composed of nanorings [13].…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of 3D plasmon talbot effect

Zappe

2014

The 9th IEEE International Conference on Nano/Micro Engineered and Molecular Systems (NEMS)

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Three-dimensional (3D) plasmon Talbot effect is experimentally investigated on three finite-sized, two-dimensional (2D) periodical arrays composed of subwavelength nanoholes with different fill factors. By using water as the output medium, both the focusing behavior and the plasmon Talbot revivals are clearly observed even when the operating wavelength is larger than the array period. And theoretically, with the output material having a refractive index of n, the operating wavelength to realize the plasmon Talbot effect can be enlarged by a factor of n-1. The integral and fractional plasmon Talbot revivals reproduce the device pattern with rich subwavelength hotspots (0.56~0.72λ) in exactly the same array period, which shows a great prospect for the low-cost, large-scale micro-and nanolithography. The preliminary experimental results indicate that the fill factor doesn't play an obvious influence on the size of the achieved plasmon Talbot hotspots.

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“…These include, e.g. negative refraction [3,4], the Talbot effect [5,6], lasing [7], cloaking [8,9,10,11] and Young's double-slit experiment [12]. The interest in such effects is due to a desire to discover new properties of these surface electromagnetic waves and to the possibility of basing novel nanoscale devices on them.…”

Section: Introductionmentioning

confidence: 99%