IQCAAP- Individual Qubit Control for Atom Array Processors
Abstract
In recent years, arrays of neutral atomic qubits have emerged as one of the most promising platforms for quantum information processing and quantum simulation. In this architecture, individual atoms are trapped in tightly focused laser beams – optical tweezers – and the integration of reconfigurable tweezer arrays with cold atom technology has led to the generation of atomic qubit arrays with hundreds of atoms. Long-range, coherent interactions between atoms are realized by coupling to high principal quantum number states – Rydberg states – and have enabled the observation of large-scale entangled states, high-fidelity two-qubit and multi-qubit gates, the discovery of a new class of non-thermalizing quantum states called quantum many-body scars and the recent realization of a topological quantum spin liquid. One aspect that all of the above demonstrations have in common is the fact that coherent interactions are realized by coupling all of the atoms in the array simultaneously to the Rydberg state. Such ‘global’ control leaves much to be desired, especially in the context of quantum algorithms where gate operations need to be atom selective. This requires individual atom addressing on fast timescales that are both compatible with the Rydberg lifetime, typically on the order of ~100 micros, and the qubit coherence times, which are on the order of approximately 1 s for qubits encoded in hyperfine states. There are multiple viable approaches for achieving individual atom selective control of the Rydberg interactions and qubit manipulations. Each approach comes with its own opportunities and challenges. For instance, small-scale quantum algorithms on 5 atoms have been realized by using acousto-optic deflectors to steer focused Rydberg excitation lasers onto selected atoms. While this demonstration is very impressive, one challenge is that only one addressing beam is available, which limits the number of gate operations that can be carried out in parallel. A second recent demonstration relied on the coherent movement of atoms which enabled 2-qubit gates by bringing selected atoms close to each other. This approach offers exciting prospects with respect to qubit connectivity. At the same time, however, moving the atoms is a slow process which further requires large amounts of space, potentially limiting the scalability of this technique.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 29, 2024
- Source ID
- FA95502310063
Entities
People
- Hannes Bernien
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Chicago