n 型ドープ GaAs 量子細線の発光および発光励起スペクトル測定

東京大学物性研究所 ,CREST （ JST ） ,Bell Lab

井原章之 , 早水裕平 , 吉田正裕 , 秋山英文 ,

Loren N.Pfeiffer,Ken W.West

１、 introduction

２、 sample

３、 PL and PLE of wire

４、 electron density dependence

５、 wire / arm well

６、 Theory

７、 conclusion and problems

introduction

Low dimensional electron system

Fermi Edge Singularity in 1D system ?

1D Luttinger Liquid ?

Photoluminescence (PL) and PL Excitation (PLE) Spectra in an n-type doped 1D Quantum Wire

Electron density dependence of

sample grown by CEO with MBE stem electron density

　1×1011 cm-2

Gate Voltage（ Vg）　 0.0～ 0.8V

wire density　0～ 4×105 cm-1

arm density 0～ 1.3×1011

cm-2

Temperature

　 5K (Liquid He)

PL and PLE of wirePLE　～

same information with absorption spectrum

1.55 1.57 1.59 1.61 1.63 1.65

wire HH

PLE

PLstem

LH

stem HH

arm HH

Photon Energy (eV)

arm LH

PL

and

PLE

Inte

nsity

(ar

b.un

its)

1.5721.5681.564

Photon Energy (eV)

LH： light hole

HH： heavy hole

Vg=0.15V

electron density dependence

1.5721.5681.564Photon Energy (eV)

PL

and

PLE

Inte

nsity

(ar

b.un

it)

1.5721.5681.564Photon Energy (eV)

0.0V

0.1V

0.15V

0.2V

0.3V

density

density

nn1D1D

HH

LL0.3V

0.35V

0.4V

0.5V

0.6V

0.7V

ω2

ω1

BE FE

FES

？PL PLE

(arb

. uni

ts)

PL

and

PLE

Inte

nsity

(ar

b.un

it)

1.5701.5681.566

Photon Energy (eV)

Trion Binding Energy

ω2ω1

PL PLE

excitation

0.0V

0.1V

0.15V

2.04meV2.33meV

1.97meV

EB

(arb

. uni

ts)

EB ～ 2meV

1.574

1.572

1.570

1.568

1.566

1.564Pea

k En

ergy

(eV

)

0.80.60.40.20.0

Voltage

PLE peak shift and PL width

h

eF m

mE 1

ω2

ω1

Band Edge (70% height)

Fermi Edge (70% height)

？

PL PLE

1.574

1.572

1.570

1.568

1.566

1.564Pea

k En

ergy

(eV

)0.80.60.40.20.0

Voltage

wire / arm

1.586

1.584

1.582

Pea

k En

ergy

(eV

)

0.80.60.40.2

Voltage

PL a

nd P

LE In

tens

ity (a

rb.u

nits

)

1.5881.5841.580

Photon Energy (eV)

wire

arm

ω2

ω1

ω2

ω1

ω2ω1

BE

FE

PL PLE

Band Edge (70%)

Fermi Edge (70%)

h

eF m

mE 1

1.5meV

4

3

2

1

0

Ener

gy (m

eV)

0.80.60.40.20.0

Voltage

EF

4

3

2

1

0

Ener

gy (m

eV)

0.80.60.40.2

Voltage

EF

Theory wire

arm

EB ～2meV

(ω2 ｰ ω1)

(ω2 ｰ ω1)

～ 1.5meV 1)( I

00 　　 0

1

)( 21

awhere

EaE BF

　　

How does FES change with EF ?

Peak shift

Line shape

EB

(ω2 ｰ ω1)

Conclusion and problems

We succeed to get electron density dependence of 1D PLE which differs from 2D PLE !!

1. Monolayer fluctuation ?

2. High electron density ?

3. Higher binding energy ?

4. Lower temperature ?

We are just doing the process of new samples !!

stage

dataPL

and

PLE

Inte

nsity

(ar

b.un

it)

1.5841.580Photon Energy (eV)

～ 1.5meV PL a

nd P

LE In

tens

ity (a

rb.u

nits

)1.5881.5841.580

Photon Energy (eV)

PL a

nd P

LE In

tens

ity (a

rb.u

nits

)

1.5881.5841.580

Photon Energy (eV)

data

PL

and

PLE

Int

ensi

ty (

arb.

units

)

1.5761.5721.5681.564

Photon Energy (eV)

1.1

0.8

0.2

1.5

1.8

0.5

EF

（ meV）

1.1

0.8

0.2

1.5

1.8

0.5

EF

（ meV）

V. Huard et al. Phys. Rev. Lett. 84 (2000) 187

arm wire

PL

and

PLE

Int

ensi

ty (

arb.

units

)

1.5701.5681.566

Photon Energy (eV)

Data - wirePho

tolu

min

esce

nce

Inte

nsity

(ar

b.un

it)

1.56751.5650Photon Energy (eV)