Unexpected Electron-Pairing in Integer Quantum Hall Effect
|일시||Sep. 22 (Fri.), 04:00 PM|
|장소||E6-2. 1st fl. #1323|
|연사||Dr. GilHo Lee / Department of Physics, POSTECH|
“Unexpected Electron-Pairing in Integer Quantum Hall Effect”
Dr. HyungKook Choi / Department of Physics, Chonbuk National University
Sep. 22 (Fri.), 04:00 PM
E6-2. 1st fl. #1323
Electronic interferometry has played a significant role in investigating some of the most fundamental and subtle issues of quantum physics, such as decoherence, entanglement and complementarity etc. Recently, we report on a novel phenomenon observed in an electronic Fabry-Perot Interferometer (eFPI) operating in the integer quantum Hall effect (IQHE) [1, 2], which revealed that the period of the Aharonov–Bohm (AB) oscillations drops by a half at bulk filling >2.5, accompanied by an interfering charge e*=2e. Although charge e is observed when the visibility is low, the single-particle interference is invariably fully dephased. Counterintuitively, the halved interference periodicity is determined by the area enclosed by the second-inner edge channel, separating the v = 1 and v = 2 regions, and not by the area within the outermost interfering channel. Such pairing is not observed in a Mach–Zehnder interferometer (MZI). A combination of an MZI and an FPI elucidates the role of the second-inner edge mode, as well as the formation of paired–electrons quasiparticles. The results suggest that a neutral chiral edge mode plays a crucial role in the pairing phenomenon. In this talk, I will briefly review the basics of electronic interferometry in the quantum Hall regime and then discuss about unexpected electron pairing.
 H. K. Choi et al., Nat. Commun. 6, 7435 (2015).
 I. Sivan et al., submitted to PRB