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

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 ? Electron density dependence of Photoluminescence (PL) and PL Excitation (PLE) Spectra in an n-type doped 1D Quantum Wire

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 wire PLE　～ same information with absorption spectrum LH：light hole HH：heavy hole Vg=0.15V wire HH PLE arm LH stem LH arm HH PL stem HH Photon Energy (eV)

electron density dependence PL PLE BE FE ？ H 0.7V 0.3V (arb. units) 0.6V 0.2V 0.5V ω1 density 0.15V 0.4V n1D 0.35V 0.1V ω2 0.3V L FES 0.0V

Trion Binding Energy PL PLE 0.15V (arb. units) ω1 ω2 excitation 0.1V EB ～2meV EB 2.33meV 2.04meV 1.97meV 0.0V

PLE peak shift and PL width PL PLE ？ ω2 Fermi Edge (70% height) ω1 Band Edge (70% height)

wire / arm wire PL PLE ω2 Fermi Edge (70%) ω1 Band Edge (70%) ω2 ω1 ω2 FE ω1 1.5meV BE arm

Theory wire (ω2ｰω1) How does FES change with EF ? Peak shift EB ～2meV (ω2ｰω1) arm (ω2ｰω1) Line shape ～1.5meV EB

Conclusion and problems We succeed to get electron density dependence of 1D PLE which differs from 2D PLE !! • Monolayer fluctuation ? • High electron density ? • Higher binding energy ? • Lower temperature ? We are just doing the process of new samples !!

stage

data ～1.5meV

data EF arm EF wire （meV）（meV） 1.8 1.8 1.5 1.5 1.1 1.1 0.8 0.8 0.5 0.5 0.2 0.2 V. Huard et al. Phys. Rev. Lett. 84 (2000) 187

Data - wire

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