Year: 2019
Type: article
Abstract: We demonstrate key multi-qubit quantum-logic primitives in a dual-species trapped-ion system based on $${}^{40}$$ 40 Ca $${}^{+}$$ + and $${}^{88}$$ 88 Sr $${}^{+}$$ + ions, using two optical qubits with quantum-logic-control frequencies in the red to near-infrared range. With all ionization, cooling, and control wavelengths in a wavelength band similar for the two species and centered in the visible, and with a favorable mass ratio for sympathetic cooling, this pair is a promising candidate for scalable quantum information processing. Same-species and dual-species two-qubit gates, based on the Mølmer–Sørensen interaction and performed in a cryogenic surface-electrode trap, are characterized via the fidelity of generated entangled states; we achieve fidelities of 98.8(2)% and 97.5(2)% in Ca $${}^{+}$$ + –Ca $${}^{+}$$ + and Sr $${}^{+}$$ + –Sr $${}^{+}$$ + gates, respectively. For a similar Ca $${}^{+}$$ + –Sr $${}^{+}$$ + gate, we achieve a fidelity of 94.3(3)%, and carrying out a Sr $${}^{+}$$ + –Sr $${}^{+}$$ + gate performed with a Ca $${}^{+}$$ + sympathetic cooling ion in a Sr $${}^{+}$$ + –Ca $${}^{+}$$
Source: npj Quantum Information
Institutions: MIT Lincoln Laboratory, Massachusetts Institute of Technology
Language: Latvian
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,490
OpenAlex ID: W2990803231