We present an electron interferometer defined purely by electrostatic gating in an encapsulated bilayer graphene. This minimizes possible sample degradation introduced by conventional etching methods when preparing quantum devices. The device quality is demonstrated by observing Aharonov-Bohm (AB) oscillations with a period of h/e, h/2e, h/3e, and h/4e, witnessing a coherence length of many microns. The AB oscillations as well as the type of carriers (electrons or holes) are seamlessly tunable with gating. The coherence length longer than the ring perimeter and semiclassical trajectory of the carrier are established from the analysis of the temperature and magnetic field dependence of the oscillations. Our gate-defined ring geometry has the potential to evolve into a platform for exploring correlated quantum states such as superconductivity in interferometers in twisted bilayer graphene.

中文翻译：

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双层石墨烯中的门限电子干涉仪

我们提出了一种纯粹由封装双层石墨烯中的静电门控定义的电子干涉仪。这最大限度地减少了在制备量子器件时由传统蚀刻方法引入的可能的样品降解。通过观察周期为h / e、h /2 e、h /3 e和h /4 e的 Aharonov-Bohm (AB) 振荡来证明器件质量，见证了许多微米的相干长度。AB 振荡以及载流子的类型（电子或空穴）可通过选通无缝调节。通过分析振荡的温度和磁场依赖性，确定了比环周长和半经典轨道长的相干长度。我们的门定义环几何有可能发展成为探索相关量子态的平台，例如扭曲双层石墨烯干涉仪中的超导性。