１．【有機半導体の非線形共振器量子電磁力学】１．【有機半導体の非線形共振器量子電磁力学】１．【有機半導体の非線形共振器量子電磁力学】１．【有機半導体の非線形共振器量子電磁力学】

①有機有機有機有機色素を含む色素を含む色素を含む色素を含む1DPCにおける強結合・超強における強結合・超強における強結合・超強における強結合・超強結合結合結合結合

（（（（PIC-J,PTCBI））））

[1]共振器量子電磁力学

[2]J会合体における共振器ポラリトンの観測

[3]非発光性の有機分子系における共振器ポラリトンの観測

[4]共振器ポラリトンの非線形光学効果

[5]今後の展望～超強結合を目指して～

Cavity Quantum Electrodynamics

κ：photon decay rate of the cavity

γ：non-resonant decay rate of the

atom

ɡ ：atom-photon coupling parameter

γ

κɡ

Interaction between light and matter in microcavity

Various type of microcavity

Relative strength of the atom-cavity interaction

is determined by 3 parameters

Atom-cavity interaction can be classified into two regime

Weak Coupling

ɡ < κ , γ

Irreversible process

Strong Coupling

ɡ > κ , γReversible process

K. Vahala, Nature, 424, 839 (2003).

The interaction between light and matter in

microcavity is different from that in free space.

Because photon and atom or exciton in the cavity

are coupled.

[1]共振器量子電磁力学

Strong coupling regime: Cavity Polariton

γ

κg0

g0 > κ , γ

Interaction between the photon in the cavity and the atom

is reversible

Normal mode splitting

(Vacuum field Rabi splitting)

Cavity polariton

(in condensed matter)

Cavity polariton in MC with GaAs QW

C. Weisbuch et al., Phys. Rev. Lett., 69, 3314 (1992).

Polariton dispersion curve

shows “anti-crossing”.

-Bose-Einstein condensation

-Polariton lasing

-Ultrafast optical switching

-Micro parametric amplifier

-Quantum computing

photon exciton0ω0ω

Energy exchange

[1]共振器量子電磁力学

Cavity Polariton in organic systems

Large Rabi splitting can be observed in organic systems even at room temperature

because of thier large oscillator strength.

D. Lidzey et al., Nature., 395, 53 (1998).

S. Gambino et al., ACS Photonics, 1, 1042 (2014).

Rabi splitting >1eV

Porphyrin derivative

Squaraine dye

Ultra-strong coupling

J aggregates Organic semiconductor single crystal

At First, vacuum field Rabi splitting was observed in atomic system

and then observed in semiconductor quantum well or quantum dot system.

[1]共振器量子電磁力学

One dimensional photonic crystal with PIC J aggregate

1D-Photonic crystal microcavity + PIC J aggregate

Linear properties

- observation of cavity polariton using PIC J aggregate

High index Low indexCavity layer

[2]J会合体における共振器ポラリトンの観測

One-Dimensional Photonic Crystal=1DPC

1DPC is the structure

whose refractive index was periodically modulated in one-direction.

・・・ ・・・

defect layer：X

・・・ ・・・

A B

nAdA=nBdB=λ/4 nxdx=λ/2

Cavity typeDBR type

0.0

0.2

0.4

0.6

0.8

1.0

0.0

0.2

0.4

0.6

0.8

1.0

Tra

nsm

itta

nce

Frequency

Tra

nsm

itta

nce

Frequency

Photonic band gap

Photon localization state

Photon Confinement=

Large optical density of state

quarter wave stacks of two dielectrics with different refractive indices

[2]J会合体における共振器ポラリトンの観測

J aggregate

J aggregate ・・・the transition dipole moment direction of molecules is coplanar and in-line

Transition dipole moment

monomerJ aggregate H aggregate

54.7° 90°0°

HJ monomer

φ

E

Monomer (methanol solution)

J aggregate (PVA film)

J-band

The configuration of molecular aggregation drastically changes the absorption and florescence properties of the dye

molecules, which is depend on the relative orientation of the transition moment vector of the molecule in the aggregate.

[2]J会合体における共振器ポラリトンの観測

Fabrication of the 1DPC sample

DBR DBR

Light

Dye doped film

The thickness of the cavity layer was gradually and intentionally changed by applying mechanical pressure.

The cavity layer is wedge-shaped and the cavity resonance shifts

by changing the incident light position.

[2]J会合体における共振器ポラリトンの観測

Observation of cavity polariton

Incident position dependence on transmission spectra

Rabi splitting ～49.2eV

A typical anti-crossing dispersion curve

with upper and lower polariton branches was observed.

Cavity polariton was successfully observed

at room temperature.

@RT

@RT

[2]J会合体における共振器ポラリトンの観測

Jaynes-Cummings model analysis

Jaynes-Cummings Ladder

A coupled atom-photon system with a coupling constant of ɡ.

In linear regime (n is small)

Polariton doublet

Full quantum treatment of the two-level system interacting single light mode.

The first excited state consisted of a doublet.

number state

[2]J会合体における共振器ポラリトンの観測

Dye concentration dependence of Rabi splitting

[2]J会合体における共振器ポラリトンの観測

PIC/gelatin weight ratio

0.00 0.025 0.050 0.10 0.15 0.20 0.40 0.60

∆� ∝ �

∆� �2��ħ�

� �

真空Rabi分裂エネルギー

One dimensional photonic crystal

with dye molecules inserted between HTO nano-sheets

[3]非発光性の有機分子系における共振器ポラリトンの観測

1D-Photonic crystal microcavity + dye molecules inserted between HTO nano-sheets

High index Low indexCavity layer

非発光の物質を用いた共振器ポラリトン

[3]非発光性の有機分子系における共振器ポラリトンの観測

発光が消光したPIC J-会合体-

HTOナノシート複合体を挿入した微小共振器を作製し透過・発光スペクトル

を測定

PIC-HTOナノシート複合体の吸収ピークエネルギー近傍で共振器モードが分裂

非発光の物質を用いた

共振器ポラリトン

Ultrafast transient transmission spectroscopy

Signal :1160nm

(SHG:580nm)

1 kHz, 50fs

[4]共振器ポラリトンの非線形光学効果

Transient transmission in strong excitation

Intensity dependence on transmission spectra Transient transmission in strong excitation

Kinetics of differential transmission

Polariton doublet AC Stark triplet210fs

Kenta Ishii, Shunsuke Nakanishi and Noriaki Tsurumachi

Appl. Phys. Lett., 103, 013301 (2013).

4.5nJAC Stark triplet

First observation of AC Stark triplet in organics

[4]共振器ポラリトンの非線形光学効果

Jaynes-Cummings model analysis

Jaynes-Cummings Ladder

A coupled atom-photon system with a coupling constant of ɡ.

In nonlinear regime (n is large)

AC Stark triplet (Mollow triplet)

Observation of AC Stark triplet in InGaAs QW system.

F. Quochi, et al. Phys. Rev. Lett., 80, 4733 (1998)

three transition are possible

In the classical point of view, this triplet is

attributed to the absorption saturation.

strong

weak

Photon number

[4]共振器ポラリトンの非線形光学効果

Summary

- observation of cavity polariton using PIC J aggregate

- observation of ultrafast transition between polariton doublet and AC Stark triplet

We investigated optical properties of a 1D-PC microcavity with PIC J aggregates.

Vacuum field Rabi splitting

Cavity polariton

AC Stark triplet

Mollow triplet

atom

M. Raizen et al.

PRL(1989)

C. Yu et al.

PRL(1997)

Inorganic

Semiconductor

QW

C. Weisbuch et al.

PRL(1992)

F. Quochi et al.

PRL(1998)

organic

D. Lidzey et al.

Nature(1998)This Work

APL(2013)

Kenta Ishii, Shunsuke Nakanishi and Noriaki Tsurumachi, Appl. Phys. Lett., 103, 013301 (2013).

[4]共振器ポラリトンの非線形光学効果

Dye concentration dependence of spectral triplet

[4]共振器ポラリトンの非線形光学効果

Coming soon

Future Plan

[5]今後の展望～超強結合を目指して～

Optical frequency (THz)ω0

Δω

ωω ∆~0

超強結合

Rabi分裂エネルギーと励起子遷移エネルギーが同程度になると超強結合と呼ばれる

新しい量子相が現れる