Quantum Plasmonics

第七组马润泽 边珂 李亚楠 王硕 闪普甲 张玺

Quantum plasmonicsM. S. Tame1*, K. R. McEnery1,2, ¸S. K. Özdemir3, J. Lee4, S. A. Maier1* and M. S. Kim2, 2013, Nature physics

surface plasmons: electromagnetic excitations coupled to electron charge density waves on metal–dielectric interfaces or localized on metallic nanostructuresenable the confinement of light to scales far below that of conventional optics;suffer from large losses

Quantum plasmonicsbuild devices that can exploit lossy nature for controlling dissipative quantum dynamicscombine modern plasmonics with quantum optics, study the fundamental physics of surface plasmons and the realization of quantum-controlled devices, including single-photon sources, transistors and ultra-compact circuitry at the nanoscale.

quantum plasmonics: descripe surface plasmons using quantum mechanics

1950s, Bohm and Pines, with work by Pines providing the very first model for quantizing plasma waves in metals;

Hopfield, provided a quantum model for the polarization field describing the response of matter to light(did not consider loss);

Ritchie,a surface plasma wave (SPW);

Elson and Ritchie, used Hopfield's approach to provide the first quantizeddescription of SPWs as `SPPs‘;

Huttner and Barnett, `microscopic' quantization method, extending Hopfield'sapproach to polaritons in dispersive and lossy media(consider loss);

A `macroscopic' approach has been developed using Green's functions

Quantization of SPWsQuantize the electromagnetic field by accounting for the dispersive properties of the metal via the collective response of the electrons(1)classical mode description(2) discretization of classical modes(3) quantization via the correspondence principleSPP: solve Maxwell‘s equations ， a general form of the vector potential A(r;t )→ a virtual square of area S = Lx *Ly is introduced on the surface. ， a discretized form for A(r;t ) → Use the quantized Hamiltonian of a harmonic oscillator,including annihilation and creation operatorsonly change :the mode function uK(r) which represents the classical wavelike properties of the excitationLSP:u(r) differ from r

Optical confinement: traditional

+=

 

Optical confinement: plasmon

Optical fiber or cavity wall.

  Surface plasmon polariton.

 

Survival of entanglement

As shown in Figs, polarization-entangled photon converted into and back to from SPP remain polarization-entangled.

Reference:1. Paul G. Kwiat, etc, New High-Intensity

Source of Polarization-Entangled Photon pairs, Phys. Rev. Lett. 75, 4337(1995)

2. E. Altewisher, etc, Plasmon-assisted transmission of entangled photons, Nature 418, 304(2002)

Decoherence and loss

Reference:1. Giuliana Di Martino etc, Quantum Statistics of Surface Plasmon Plaritons in Metallic Stripe

Wave guides, Nano Lett. 12, 2504(2012)

Decoherence and loss

Wave-particle duality

Quantum size effectthe continuous electronic conductional band,

valid at macroscopic scales, break up into discrete states when dimensions are small enough, making the Drude model no longer valid

quantum tunnelling

QR:quantum regime

Part III ： Single emitters coupled to SPPs

1.Weak coupling regime:

2.Strong coupling regime:

Coherent energy transfer between emitter and Spp field

3. Some applications ： Spp-induced Pucell effect, High-Q plasmonic cavity, nanoatenna,ect

Plasmon spectrum of GNP(black) and fluorescence spectrum of single molecule(red)

CCD image of singe molecule without GNP

importance of the antenna resonance in the excitation enhancement

16

Schematic figure of single emitter coupled with nanowire plasmon waveguide

a high degree of correlation was seen between the time traces of the fluorescence counts from the quantum dot(red) and the end of the coupled wire(blue)

Second-order correlation function of quantum dot fluorescence.

Second-order correlation function between fluorescence of the quantum dot and scattering from the nanowire end

Simulation of the propagation of surface plasmom in this DBRs cavity.

Stop band

The resonance of cavity

The modified fluorescence spectrum of QD in this cavity

The cavity-induced fluorescence enhancement

The modified fluorescence spectrum of NV center in this cavity

Placing a silver/superconducting nanowire waveguide on top of a germanium field-effect transistor

Detection

Various types of external quantum sources (parametric down-conversion, an optical parametric oscillator, emitters in cryostats).

Embed emitters on the waveguides and excite them with an external classical source.

Fix NV centers onto the tip-apex of a near-field optical microscope.

Develop on-chip electrically driven SPP sources.

Manipulation

A range of waveguides

LRSPP （ Long － range surface plasmon － polariton ） waveguide

A combination of different waveguides

Hybrid platform of metallic and dielectric waveguides

Use nanoparticles supporting coupled LSPs

More complex waveguide structure

Perspectives

Realize functioning reliable devices.

How to deal with loss.