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【Abstract】

The Kitaev chain is a simple toy model that features Majorana bound states as its solution. Compared to an elementary tight-binding chain of electrons, the main added ingredient is spin-triplet superconducting coupling between neighboring sites. Such coupling can be observed via triplet Cooper-pair splitting processes, where a Cooper pair is separated into two single electrons with the same spin. In this talk, we first report on an equal-spin Cooper-pair splitter, realized using two quantum dots connected via a narrow strip of semiconductor-superconductor hybrid. We further show that the electron couplings in this system are highly controllable via electric gating. This tunability allows us to operate this device as a minimal, two-site Kitaev chain. At a fine-tuned parameter sweet spot, we can observe and verify all experimentally accessible properties of the theoretically predicted “poor man’s Majorana” bound states. We conclude with a preview of ongoing work and possible next steps.