Practical quantum computers require a large network of highly coherent qubits, interconnected in a design robust against errors. Donor spins in silicon provide state-of-the-art coherence and quantum gate fidelities, in a platform adapted from industrial semiconductor processing. Here we present a scalable design for a silicon quantum processor that does not require precise donor placement and leaves ample space for the routing of interconnects and readout devices. We introduce the flip-flop qubit, a combination of the electron-nuclear spin states of a phosphorus donor that can be controlled by microwave electric fields. Two-qubit gates exploit a second-order electric dipole-dipole interaction, allowing selective coupling beyond the nearest-neighbor, at separations of hundreds of nanometers, while microwave resonators can extend the entanglement to macroscopic distances. We predict gate fidelities within fault-tolerance thresholds using realistic noise models. This design provides a realizable blueprint for scalable spin-based quantum computers in silicon.
@article{osti_1394154,
author = {Tosi, Guilherme and Mohiyaddin, Fahd A. and Schmitt, Vivien and Tenberg, Stefanie and Rahman, Rajib and Klimeck, Gerhard and Morello, Andrea},
title = {Silicon quantum processor with robust long-distance qubit couplings},
annote = {Practical quantum computers require a large network of highly coherent qubits, interconnected in a design robust against errors. Donor spins in silicon provide state-of-the-art coherence and quantum gate fidelities, in a platform adapted from industrial semiconductor processing. Here we present a scalable design for a silicon quantum processor that does not require precise donor placement and leaves ample space for the routing of interconnects and readout devices. We introduce the flip-flop qubit, a combination of the electron-nuclear spin states of a phosphorus donor that can be controlled by microwave electric fields. Two-qubit gates exploit a second-order electric dipole-dipole interaction, allowing selective coupling beyond the nearest-neighbor, at separations of hundreds of nanometers, while microwave resonators can extend the entanglement to macroscopic distances. We predict gate fidelities within fault-tolerance thresholds using realistic noise models. This design provides a realizable blueprint for scalable spin-based quantum computers in silicon.},
doi = {10.1038/s41467-017-00378-x},
url = {https://www.osti.gov/biblio/1394154},
journal = {Nature Communications},
issn = {ISSN 2041-1723},
number = {1},
volume = {8},
place = {United States},
publisher = {Nature Publishing Group},
year = {2017},
month = {09}}
Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, Vol. 452, Issue 1954, p. 2551-2577https://doi.org/10.1098/rspa.1996.0136