Mode dependency of quantum decoherence studied via an Aharonov-Bohm interferometer
Tung-Sheng Lo1,2*, Yiping Lin1, Phillip M. Wu3, Dah-Chin Ling4, C. C. Chi1,5
1Department of Physics, National Tsing-Hua University, Hsinchu, Taiwan
2Institute of Physics, Academia Sinica, Taipei, Taiwan
3Department of Applied Physics and Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California, USA
4Department of Physics, Tamkang University, New Taipei City, Taiwan
5Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing-Hua University, Hsinchu, Taiwan
* presenting author:Tung-Sheng Lo,
We investigate the dependence of decoherence on the mode number M in a multiple-mode Aharonov-Bohm (AB) interferometer. The design of the AB interferometer allows us to precisely determine M by the additivity rule of ballistic conductors; meanwhile, the decoherence rate is simultaneously deduced by the variance of the AB oscillation amplitude. The AB amplitude decreases and fluctuates with depopulating M. Moreover, the normalized amplitude exhibits a maximum at a specific M (∼ 9). Data analysis reveals that the charge-fluctuation-induced dephasing, which depends on the geometry and the charge relaxation resistance of the system, plays the essential role in the decoherence process. Our results suggest that the phase coherence, in principle, can be optimized using a deliberated design and pave a way toward the engineering of quantum coherence.

Keywords: ballistic one-dimensional transport, Aharonov-Bohm interferometer, quantum coherence