Nanowerk July 7, 2022 Because of the combination of long coherence times and large interaction strengths, one of the leading experimental platforms for cavity QED involves coupling a superconducting circuit to a 3D microwave cavity. In this work. An international team of researchers (USA – University of Chicago, University Rutgers, University of Chicago, UC Berkeley, South Korea) demonstrated a variety of protocols for universal single-mode quantum control applicable across all cavity modes, using only a single drive line. They achieved this by developing a straightforward flute method for creating monolithic superconducting microwave cavities that reduces loss while simultaneously allowing control […]
Category Archives: Quantum memory
Quantum network nodes with warm atoms
Science Daily June 24, 2022 An international team of researchers (Switzerland, Germany) built and successfully interfaced a single-photon source based on cavity-enhanced spontaneous parametric down-conversion in periodically poled potassium titanyl phosphate and a matched memory based on electromagnetically induced transparency in warm 87Rb vapor. The bandwidth of the photons emitted by the source was 370MHz, which is within the accepted bandwidth of the memory. The experimental complexity was kept low, with all components operating at or above room temperature. Read-out noise of the memory was considerably reduced by exploiting polarization selection rules in the hyperfine structure of spin-polarized atoms. They […]
Scientists realize noiseless photon-echo protocol
Phys.org August 16, 2021 The intense spontaneous noise emission generated by photon echo is a fundamental tool for the manipulation of electromagnetic fields. However, it has the same frequency as the signal, and it is impossible to separate them in principle. Researchers in China have implemented a noiseless photon echo (NLPE) protocol in Eu3+:Y2SiO5 crystal to serve as an optical quantum memory and applied a four-level atomic system to suppress the noise. They manipulated the spontaneous noise emission to have a different frequency from the signal making it easier to separate the signal from the noise emission. Though other noises […]
A milestone in quantum physics: Physicists successfully carry out the controlled transport of stored light
Nanowerk October 13, 2020 Quantum memories for light, realized with cold atomic samples as the storage medium, are prominent for their high storage efficiencies and lifetime. Researchers in Germany used ultra-cold rubidium-87 atoms as a storage medium for the light as to achieve a high level of storage efficiency and a long lifetime. They transported the stored light over 1.2 mm. They showed that the transport process and its dynamics only have a minor effect on the coherence of the storage. Extending the presented concept to longer transport distances and augmenting the number of storage sections will allow for the […]
A quantum memory that operates at telecom wavelengths
Phys.org June 15, 2020 Researchers in the Netherlands designed and fabricated the fully engineerable, device with operational wavelength of 1550 nanometers to enable the system to work in the low-loss telecommunication band wavelength. The system’s optical and mechanical resonances are fully artificial. They were able to show that the memory has a satisfactory lifetime and coherence while successfully creating the superposition state. In future studies, they plan to gain a better understanding of why the de-phasing of a quantum state, to avoid having such a short coherence, understand the underlying microscopic mechanisms, and increase the overall efficiency of the memory. […]