Scientists Get Photons to Interact, Taking Step Towards Long-Living Quantum Memory
(Phys.org) A study by international research team from NUST MISIS, Russian Quantum Center, the Ioffe Institute St. Petersburg and Karlsruhe Institute of Technology may have designed a step toward the implementation of a long-living quantum memory and the development of commercial quantum devices.
Scientists believe that individual light particles, or photons, are ideally suited for sending quantum information. Encoded with quantum data, they could literally transfer information at the speed of light. However, while photons would make for great carriers because of their speed, they don’t like to interact with each other, making it difficult to achieve quantum entanglement.
This research team obtained experimental evidence for effective interaction between microwave photons via superconductive qubits for the first time.
In their experiments, the researchers used photons with the frequency of a few GHz and the wavelength of a few centimeters. “We used superconducting cubits, which are basically artificial atoms, because they have been proven to strongly interact with light. Interaction between natural atoms and natural light is weak due to the small size of natural atoms.”
Superconducting qubits represent a leading qubit modality that is currently being pursued by industry and academia for quantum computing applications. However, they require milli-Kelvin (mK) temperatures to operate. The efforts of the scientific community have been recently focused on increasing the processing power of a quantum computer by transmitting quantum signals from one refrigerator to another. To engineer this transmission, the scientists coupled an array of eight superconducting transmon qubits to a common waveguide—a structure that guides waves, e.g., light waves.
The circuit of this work extends experiments with one and two qubits toward a full-blown quantum metamaterial, thus paving the way for large-scale applications in superconducting waveguide quantum electrodynamics.