Transmitting the quantum state of electrons across a metallic island with Coulomb interaction

The Coulomb interaction generally limits the quantum propagation of electrons. However, it can also provide a mechanism to transfer their quantum state over larger distances. Here, we demonstrate such a form of electron teleportation across a metallic island. This effect originates from the low-temperature freezing of the island's charge Q which, in the presence of a single connected electronic channel, enforces a one-to-one correspondence between incoming and outgoing electrons. Such faithful quantum state imprinting is established between well-separated injection and emission locations and evidenced through two-path interferences in the integer quantum Hall regime. The additional quantum phase of 2πQ/e, where e is the electron charge, may allow for decoherence-free entanglement of propagating electrons, and notably of flying qubits.