We report an edge-magnetoplasmon (EMP) Mach-Zehnder (MZ) interferometer in a quantum Hall system. The MZ interferometer, which is based on the interference of two EMP beams traveling in chiral one-dimensional edge channels, is constructed by tailoring edge channels with functional devices such as splitters and delay lines. We measured EMP beams transmitted through the interferometer while tuning the phase evolution along two interference paths using tunable delay lines. Clear interference patterns as a function of the phase difference ensure the MZ interference. Moreover, the MZ interferometry is applied to evaluate the EMP transport through an attenuator interposed in one of the paths. This technique will be useful for investigating the functionalities of devices in plasmonics.
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Because the splitting of EMP beams at SPj is described by Tj and Rj, which satisfy , the energy conservation does not hold in the splitting process, causing the amplitude of the interference fringes to be smaller than unity.
In this measurement, we applied −2.0 V to ones of the split-gate electrodes and 0 V to the other electrodes in order to fully open the SPs.
