Stanford engineers have come up with a simple new design for a quantum computer. In it, one atom is associated with several photons, which process and store information.

Researchers have created a simplified scheme for how a quantum computer works that entangles one atom with multiple photons.

The efficiency of quantum computers is much higher than conventional ones, it’s all about the way information is stored and processed. However, such devices have their own problems. For example, quantum effects are sensitive to vibration or heat, so quantum computers must be used at temperatures near absolute zero.

Therefore, the more complex the device of a quantum computer, the greater its computing power, and hence the design becomes larger.

But the authors of the new work came up with a new approach. They created their own design that would make the quantum computer smaller and simpler. This is a photonic circuit that uses a fiber optic cable, a beam splitter, two optical switches and an optical resonator.

Usually, if you need to build a quantum computer, you need to take about a thousand quantum emitters and integrate them into a giant photonic circuit. Our design only needs a few relatively simple components. Also, the size of the device does not increase depending on the complexity of the task.

Ben Bartlett, study lead author

The new design consists of two main parts: a ring that stores photons and a scattering device. Photons are qubits that move around a ring depending on the number assigned to them.

To encode information, the system can direct photons from the ring to the scattering unit, where they fall into a cavity containing one atom. When a photon interacts with an atom, they become entangled. In this quantum state, they can no longer be described separately, since any changes will affect all participants in the entanglement.

We can also measure the state of the atom and use photons for the operation. Therefore, we only need one controlled atomic qubit, which we use as an intermediary to indirectly control all other photonic qubits.

Ben Bartlett, study lead author

The team notes that with this design, you can run different programs. To do this, you only need to write new code to change the way and time of interaction of the atom and photons.