Abtract: A key question for platforms realizing quantum computation, simulation and communication is: How can we grow the size of a quantum system, while keeping high fidelities of single operations?
In this talk, I report on work towards this goal on two different platforms: (1) atoms in tweezer arrays and (2) quantum networks with spin qubits in diamond.
On (1), this includes building a cryogenic tweezer platform with a single-atom trap lifetime of over 6000 seconds.
On (2), I discuss how isotopically engineered diamond can offer long-lived nuclear qubits important for larger quantum networks. Furthermore, we use Gate Set Tomography to report one and two-qubit gate fidelities exceeding 99.9% for the electron and nitrogen-nuclear spin of an NV center in diamond.