Enabling large-scale fault-tolerant QC

By making the most challenging part of photonic quantum computation deterministic instead of probabilistic, Quantum Source provides a viable route towards constructing large-scale, fault-tolerant, server rack-sized quantum computers.

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Deterministic photon generation and gates

Once the conditions of cavity-QED are attained (high single-atom cooperativity), a host of valuable atom-mediated quantum operations opens up, including single-photon generation and photon-atom quantum logic gates. Every protocol cycle begins and ends with a verification stage that ensures the presence of a single atom in the trapping site (if not, that site is disabled until a new atom reloads), and the atom’s electronic state is correct.

Single-photon
generation

With only one atom trapped and high cooperativity, every excitation of the atom is guaranteed to generate exactly one photon into the resonator’s mode.

Photon-atom gates

In contrast to the atoms in the photon-generation sites, for our entanglement protocols, the other atom trapping sites are tailored to use a 3-level Λ configuration of the atom (87Rb).

In this configuration, optical fields can tune the atom to perform one out of two native gates:

  • The SWAP (in which the qubit is exchanged between the photon and the atom), and

  • The controlled-phase or CZ (in which a π phase shift is implemented only when both qubits are in the “1” state).

Quantum Source’s architecture removes the barriers to practical quantum computing using deterministic quantum interactions between single photons and single atoms.

Final Diagram

Our protocols

By repeatedly implementing short multi-photon protocols in each site, a small number of trapped atoms on each chip can generate and entangle the very large number of photons required for fault- tolerant photonic quantum computing. The deterministic nature of the gates minimizes the need for costly and complex feed-forward and switching operations that are necessary in other implementations.

Papers/tutorials

Blog

SWAP - the most fundamental unit of communication in nature

Realizing a unitary exchange of qubits between light and matter carries both fundamental and practical significances.
Read more
Read more
Read more
Paper

Extraction of a single photon from an optical pulse

Picking one photon from a laser pulse: a single-photon source for atom-mediated photonic quantum computation.
Nature Photonics
Nature Photonics
Nature Photonics
Video

Quantum Source's practical path to million-qubit computations

By making resource state generation deterministic instead of probabilistic, Quantum Source overcomes existing quantum space and efficiency challenges.
Watch the video
Watch the video
Watch the video