Carnot - efficiency based Nanoantenna Systems

Bhupendra Subedi– University of Missouri Kansas City Kansas City, MO 64111

bsr34@mail.umkc.edu

So any plasmonic nanostructures can be considered as nanoantennas (not very rigid)

Antenna: converts radiation energy to localized energy and vice versa

analogous to

phenomena in the surface of the metallic nanostructures (optical frequency) called Localized Surface Plasmon Resonance

(LSPR).

Wave strikes metal nanostructures, energy is transferredto electrons and resonance occurs when mom. of photons = mom of polaritons

[1] Javier Aizpurua, "Quantum kisses between optical nanoantennas”, mappingignorance (2013).

θ

ε1

ε2

E0x

y

Φ = Φ (r,θ ,ϕ ), scalar _ potentialE1 = − ∇ Φ 1and∇ 2Φ 1 = 0

E2 = − ∇ Φ 2and∇ 2Φ 2 = 0

We need to solve Laplace Equation

Electric Field in x direction is given by:

Φ 0 = −E0x = −E0rcosθ ,andΦ 2 = Φ scatter + Φ 0

Φdipole = p

4πε2cosθr2

= −E0rcosθ

Applied _Field = E0ε1 −ε2

ε1 +2ε2a3cosθr2

E0

x

y

ε1

ε2

Shows: Field outside = Field due to dipole + Applied_Field

So nanoantennas cover wide spectrum of applications

.# Areas of Application Application and devices

1. Nanophotonics detectors, filters and lasers eg. maskless optical lithography, NSOM

2. Plasmonic Solar Cells rectennas using ALD technology

3. Metamaterials optical/EM sheilding and invisibility cloaks

4. Chemical and bio/medical sensing and optical devices

super lenses for medical sensing, medical cancer treatment; gases and radiation sensors

5. On-Chip Interconnect on-chip nanoantennas

Need for different infrastructures such as modeling software and fabrication engineering

Conventional Antennas Nanoantennas

• Fed by real current, EM resonance causes waves

• Fed by localized current, Surface Plasmon Polaritons causes waves

• Demands classical treatment • Demands QM treatment

• Dissipated power related to voltage and current

• Dissipated power related to Green’s function tensor and Local density of state (LDOS)

Need for optimized antenna element and skin depth

• Long lifetime of exiton polariton causes recombination

P0

=I 2

3πη∆l

λ0

• Large ohmic losses and relative finite skin depth decreasing efficiency and

unfocussed radiation pattern

η =1− TcoldThot

Simple idea: Recycling of the wasted

heat from the cold sink

Hotter Sink gets more

hotter

Colder Sink gets

more colder

Increases

efficiency

1. Absorbing antenna as

close to Cold sink as possible

Say ¼ wave distance

=>short-circuit (unbalanced

Voltage condition)

Solution:

Coupling capacitance

Coupling Capacitance, A. Boswell, “amasci”

Tuned capacitive

Coupling

Improves power

Radiation by 100

folds

Avoids short-circuit; ehhances absorption

Nano-rectifiers

Not easy to channel heat radiations

These waves are vibrating in infra red or even THz frequency

that todays commercial rectifiers can’t handle

Nano-rectifiers 100-1,000 X smaller rectifiers needed

P0

=I 2

3πη∆l

λ0

Graphene based absorbing antenna

Fabry –Perot Resonance

Chamber (LSPR)

[Stamatios A. Et. Al]

Can be tuned to absorb certain wavelength

P0

=I 2

3πη∆l

λ0

[16] Maciej Klemm. "novel directional nanoantennas for single-emitter sources and wireless nano-links". International Journal of Optics, 2012(2012), 2012.

P0

=I 2

3πη∆l

λ0[1] Circuit implementation

[2] efficiency improvement

[3] good absorbing and radiating elements/ improvisation

Basically an idea,

I would do Modelling, FEKO Simulation, Implementation and what not.

P0

=I 2

3πη∆l

λ0

[1] Javier Aizpurua, "Quantum kisses between optical nanoantennas”, mappingignorance (2013).

[2] Javier Aizpurua, “Lecture given at SSOP Porquerolles, Sept. 2009

[3] Maciej Klemm. "novel directional nanoantennas for single-emitter sources and wireless nano-links". International Journal of Optics, 2012(2012), 2012

[4] A. Boswell, “amasci

Thank you

bsr34@mail.umkc.edu