Dr. Leonardo DiCarlo – Yale University
Harnessing multi-qubit entanglement in superconducting circuits
Abstract
Entanglement has traditionally played a central role in foundational discussions of quantum mechanics. The measurement of correlations between entangled quantum particles exhibits results at odds with classical behavior. With the ample confirmation of quantum mechanical predictions in experiments, entanglement has evolved from a philosophical conundrum to a key resource for quantum-based computation, cryptography and precision measurements. I will present recent results on the preparation and measurement of two- and three-qubit entanglement in superconducting integrated circuits. Our solid-state quantum processors are based on circuit quantum electrodynamics, wherein a microwave transmission-line resonator couples multiple engineered artificial atoms, enhances their quantum coherence, and allows their joint readout. Bell and Greenberger-Horne-Zeilinger states are created with simple sequences of one-qubit rotations and two-qubit conditional phase gates, and detected using quantum state tomography, witnesses, and violation of Mermin-Bell inequalities. I will show how we harness this entanglement to realize simple quantum algorithms, and survey exciting next challenges on the road to a scalable solid-state quantum computer.