Affiliation: The University of New South Wales

During the stay Prof. Sven Rogge will give a talk:

Building Quantum Matter Atom by Atom

Atomic-scale engineering reached a level of control where single-atom devices can be reproducibly fabricated. This talk focuses on single dopant atom placement in the context of engineered matter for quantum simulation and computation. Silicon offers an interesting platform for engineered quantum matter because when isotopically purified it acts as a “semiconductor vacuum” for spins. After a general introduction of quantum simulation and computation a first step towards engineered Hamiltonians for Fermionic systems in the form of atomic chains will be presented. Here strongly interacting dopants were employed to simulate a two-site Hubbard Hamiltonian at low effective temperatures with single-site resolution which allows the quantification of the entanglement entropy and Hubbard interaction strengths. To scale this approach to larger systems in-situ multi-electrode devices have been fabricated by a scanning probe hydrogen depassivation and decoration technique. Spatially resolved gated single-electron spectroscopy maps obtained ion these devices n ultra-high vacuum will be presented. Such quantum-state images of two-donor devices led to a donor based two qubit gate design that is robust in regard to variability in dopant placement. In addition to the work on donors I will also present work on single defects in silicon with a spin-orbit interaction for electrical manipulation and coupling.

The talk will be on Monday (November 18th) from 13:00 till 14:30 in the Saturn seminar room.