We consider a device which allows to create and probe single Majorana fermions, in the form of Bogoliubov quasiparticles. It is composed of two counter-propagating edge channels, each put in proximity with a superconducting region where Andreev reflection operates, and which thus converts electrons into Bogoliubov quasiparticles. The edge channels then meet at a quantum point contact where collisions can be achieved. A voltage biased version of the setup was studied in Phys. Rev. Lett. 112, 070604 (2014) and showed non-local interference phenomena and signatures of Bogoliubov quasiparticle collisions in the high frequency noise characteristics at the output, constituting an evidence of the Majorana fermion nature of these excitations. Here, voltage biased leads are replaced by single electron sources in order to achieve collisions of single Bogoliubov quasiparticles, with the major advantage that zero-frequency noise measurements are sufficient to access the intimate nature of Bogoliubov wave-packets. We compute the injection parameters of the source, and go on to investigate the Hanbury-Brown and Twiss and Hong-Ou-Mandel signal at the output, as a function of the mixing angle which controls the electron/hole component of the Bogoliubov wave-packet. In particular, information on the internal structure of the Bogoliubov quasiparticle can be recovered when such a quasiparticle collides with a pure electron. Experimental feasibility with singlet or triplet superconductors is discussed.
Electronic Hong-Ou-Mandel interferometer for multi-mode entanglement detection
我们证明了在Hong-Ou-Mandel干涉仪中通过测量零频率电流关联可以检测到介观导体中电子的多模纠缠。通过这种方法，可以进一步建立两电子输入态形成纠缠的下界。我们的结果扩展了Burkard和Loss的工作[Phys. Rev. Lett. 91，087903（2003）]，并提供了一种方法来测试涉及轨道和自旋自由度的纠缠态的存在。
