Membrane-in-the-middle quantum memory for single photons

Project funded by Croatian Science Foundation (HRZZ) (Research Projects), grant IP-2024-05-5670. Participating organisations named by the source: University of Rijeka; University of Rijeka, Faculty of Physics; Institut za fiziku. Funded amount: EUR 199,760, as stated by the source. Runs 2024-12-20 to 2027-12-19. Keywords: optomechanics, optial cavity, membrane-in-the-middle cavity, quantum memory, single photons. Source: OpenAIRE Graph, from the funder's project data (collected by OpenAIRE on 2025-08-01); national funding data, not CORDIS. Abstract given by the source: Many applications of the quantum theory, like quantum cryptography over long distances and interconnection of quantum computers, require the distribution of quantum resources, such as entanglement. Associated losses dictate the need for quantum repeaters, a key facilitator in which is a quantum memory. Different protocols for such memories have been proposed, but existing realizations fall short of combining the following desired properties in a single system: long coherence time, high efficiency, on-demand readout and compatibility with the telecom C-band. In MIMIQ.ME, we will work on the development of a wavelength-versatile memory platform for single photons (SPs) based on the principle of optomechanically induced transparency (OMIT), which can be used in conjunction with a suitable SP source to fulfil all of these requirements. We will operate the memory at room temperature and implement it in a particular optomechanical system, the membrane-in-the-middle (MIM) cavity, where the SPs are stored in a vibrational mode of an ultracoherent soft-clamped membrane resonator. We will test the platform using optical pulses, showcasing record storage times and efficiencies among optomechanical memories.We will realize a source of heralded SPs to be stored, based on spontaneous parametric down conversion in a nonlinear crystal. We will resonantly enhance the process by placing the crystal inside another cavity to form an optical parametric oscillator. Following MIMIQ.ME, we plant to measure the preservation of entanglement between generated photon pairs after storage to confirm the system works as a quantum memory. Looking further ahead, it can be used to store polarization qubits generated by on-demand SPs from semiconductor quantum dots, propelling the state of the art of quantum networks towards practical applications. This promise is further highlighted by the fact that MIM systems with soft-clamped membranes have seen room-temperature operation in the quantum regime.

Original source.

Source: OpenAIRE Graph: projects of national funders, OpenAIRE, from the project data of Croatian Science Foundation (HRZZ). Retrieved 2026-10-22. Licence: Creative Commons Attribution 4.0 (OpenAIRE Graph). Selected metadata, adapted presentation; the publisher's record is authoritative. No endorsement by the source is implied. Licence: Creative Commons Attribution 4.0 (CC BY 4.0).