Polarization-dependent photoluminescence-excitation spectra of one-dimensional exciton and continuum states in T-shaped quantum wires

Abstract

We measured polarization-dependent photoluminescence-excitation spectra of highly uniform T-shaped quantum wires at 5 K. We attribute one peak to the one-dimensional(1D)-exciton ground state and the continuous absorption band to 1D continuum states. These had similar polarization dependences. We also observed some other peaks above the 1D-exciton ground state and attribute them to exciton states consisting of excited hole subbands. These results show good agreement with a model calculation of a single electron-hole pair in T-shaped geometry with exact diagonalizations of the Coulomb interaction.

Exact solution for 2D polygonal inclusion problem in anisotropic magnetoelectroelastic full-, half-, and bimaterial-planes

“…Fig. 2 shows the geometry of a T-shaped QWR in the magnetoelectroelastic full-plane, obtained from experimental observations of Goldoni et al (1997b), Rossi et al (1997Rossi et al ( , 1999, Grundmann et al (1998), andItoh et al (2003). The T-shaped QWR is formed by intersecting two QW structures where the carrier is confined only in one direction.…”

Room-temperature excitonic absorption in quantum wires

“…The cavity length L is 512 µm, and cavity facets are uncoated. Details on sample fabrication and characterizations are discussed in separate papers [4,12,13]. The upper columns in Table I summarize the structural parameters of the 20-wire device, in comparison with those of the single-wire device used in the previous low-temperature transmission study [9].…”

“…The excited exciton, on the other hand, has a similar absorption value for both polarizations. This difference originates from the difference in the hole subbands contributing to optical transition [4].…”

“…So far, most research has relied on emission measurements such as photoluminescence (PL) [3], PL excitation (PLE) [3,4], and lasing [5,6,7,8], and there have been no measurements of quantitative direct absorption on quantum wires. We recently measured the absorption spectrum of a single T-shaped quantum wire (T-wire) embedded in an optical waveguide using straightforward waveguide-transmission spectroscopy at 5 K, and found that the one-dimensional (1D)-exciton ground state has a large modal absorption coefficient of 80 cm −1 despite the small lateral size of the T-wire, i.e., 14 nm ×6 nm [9].…”

Strong photo-absorption by a single quantum wire in waveguide-transmission measurement

“…: : : : : : Figure 2(b) shows the absorption spectrum of the single T-wire for the light polarized parallel to the arm well. The line shape 6f absoion spectrum is quite similar to PLE spectrum [5], and spectra peaks at 1.583 W, 1.590 W, and 1.595 W (shown by solid: arrows) are assignIeto Igrond-stte iton, the first d cito Consisting of excited hole subband, aid the contiuum tes,respetive .The ease absorpton above 1.600 eV s de to t ann wel..…”