Experimental observation of Coulomb drag in parallel ballistic quantum wires

✍ Scribed by P Debray; P Vasilopoulos; O Raichev; R Perrin; M Rahman; W.C Mitchel

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 94 KB
• Volume: 6
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(99)00175-7

✦ Synopsis

We report the experimental observation of Coulomb drag in two parallel, ballistic quantum wires fabricated from a high-mobility 2DEG at the interface of a AlGaAs=GaAs heterostructure and deÿned by three independent Schottky gates. The Coulomb drag resistance R D in wire 1 due to a drive current in wire 2 was measured at 1.3 K and in a magnetic ÿeld of 1 T, applied to completely suppress tunneling between the wires when their separation was small. As the widths of the wires are changed by appropriately biasing the Schottky gates, R D shows a structure with peaks whose magnitudes decrease rapidly with the distance d between the centers of the wires. These results can be understood qualitatively in the framework of recent theoretical treatments, which predict peaks in R D when the level splitting between the 1D subbands of the wires and the Fermi momentum kF are small. The peak is strongest for the lowest subbands and weakens rapidly for higher ones.