Stuttgart 2012 – wissenschaftliches Programm
Q 45.4: Vortrag
Donnerstag, 15. März 2012, 15:15–15:30, V47.01
Telecom wavelength semiconductor-superconductor based quantum emitters — •Claus Hermannstädter1,2, Hirotaka Sasakura1, Nahid A. Jahan1, Jae-Hoon Huh1, and Ikuo Suemune1 — 1Hokkaido University, Sapporo, Japan — 2JSPS
Practical integrated single and entangled photon-pair sources in the telecommunication band are attracting plenteous attention for on-chip and fiber-based technologies. We use semiconductor quantum dot (QD) and light emitting diode (LED) structures grown on InP substrates as quantum emitters in the spectral range between 1.3 and 1.6 µm.
We present one approach to realize a source of single photons and polarization entangled photon-pairs by isolating a small number of QDs inside InGaAlAs nano-mesas of around 150 nm diameter. For enhanced photon extraction, the nano-mesas are embedded in metal and the InP substrate is removed [Jpn. J. Appl. Phys. 50, 06GG02 (2011); New. J. Phys., submitted (2011)]. Another approach for the realization of entangled photon-pairs is the concept of Cooper-pair (Josephson) LEDs [PRL 103, 187001 (2009); PRL 107, 157403 (2011)]. InGaAs LEDs are processed with superconducting Niobium electrodes for the injection of electron Cooper-pairs. The presence of these Cooper-pairs at the p-n-junction leads to their radiative recombination with two normal holes and thus the simultaneous generation of entangled photon-pairs. Both demonstrated approaches have the potential to be combined to "Cooper-pair QD-LEDs" and allow for integration on semiconductor chips as parts of larger devices. Moreover, the target wavelength of 1.55 µm for application in silica fiber networks is successfully covered.