Single-photon detection of THz-waves using quantum dots

✍ Scribed by S Komiyama; O Astafiev; V Antonov; T Kutsuwa

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 392 KB
• Volume: 63
• Category: Article
• ISSN: 0167-9317
• DOI: 10.1016/s0167-9317(02)00608-1

✦ Synopsis

We demonstrate two mechanisms of single photon detection in the THz spectral region by using gate-voltageinduced lateral GaAs /AlGaAs quantum dots (QDs). Firstly, a QD in strong magnetic fields (B 5 3-4 T) is operated as a single electron transistor (SETs). THz-photons (1.8-1.5 THz) excite the QD via cyclotron resonance, and electrical polarization is thereby induced within the QD. The polarization, in turn, affects the SET conductance. Secondly, a SET with parallel double QDs is operated without magnetic fields, where GHz-photons (about 500 GHz) excite and ionize one of the QDs, which is, in turn, probed by the other QD to change the SET conductance.