by Amara Graps
“Does your company have the necessary Intellectual Property Rights (IPR) to ensure freedom to operate and adequate protection of the idea?”
This query is one of the checks for every application to the European Innovation Council (EIC), an ambitious innovation initiative by Europe, with a budget of €10B. Reading the stories in the patent record can educate you on an entire field. Let’s take a look at a recent EIC fund recipient: Paris-based, Welinq, which won a €2.5M EIC grant last April, for developing a cold atom solution for quantum memory, as QCR reported earlier here.
The writers of this quantum memory patent application listed three demonstrations for prior art, which spanned the period 2015 to 2019. Those research milestones simultaneously stepped me through the sub-field’s science, at the same time as their research ecosystem.
The Diversification of the Quantum Memories Research Field
The first demonstration, seen in paper: Gouraud et al. 2015, used atoms cooled in a magneto-optical trap (MOT) on a nanoscale optical fiber to show fibered quantum memory. If you look at that paper’s research ecosystem with Connected Papers (C.P.), the research ecosystem shows closely-spaced clusters of high-citation research. These researchers are learning from each other, performing similar research (C.P. will show you titles and abstracts and links). See the next figure. For example, the research by Vetsch et al., 2009, from Institut fuer Physik, Johannes Gutenberg-Universitaet in Mainz, is cited 592 times, the research by Thompson et al., 2003, from Harvard and MIT, was cited is times, and the research by Goban, et al., 2015, from Caltech and the Korea Institute of Science and Technology, is cited 379 times.
Let’s jump ahead to the third demonstration research by Corzo et al., 2019, in prior art of that same patent application. When centered on Corzo et al, in Connected Papers, the research ecosystem has changed. What happened? After accounting for a time, which is four years more recent, these researchers are less-clustered, i.e., following more dissimilar research directions. Trapped, cold neutral atoms are still common, but not universal, and there are cavities, crystals, and other manipulations of the photonic state, which are not necessarily for quantum memory.
Indeed, if one looks at new funding from this 2019-20 period, there were new strategies suggested, for example, this ERC grant by the European Commission: Quantum Repeater Architectures Based on Quantum Memories and Photonic Encoding. This team’s specialty is vacancy centers in diamond, see the principal investigator: Tim Schroeder’s work at Google Scholar. His team and collaborators work on the interfaces between fiber, waveguides, and their sources: vacancy centers in diamond, for quantum networks. For example, see this research by Bopp et al., 2023, ‘Sawfish’ Photonic Crystal Cavity for Near-Unity Emitter-to-Fiber Interfacing in Quantum Network Applications. In Bopp et al.’s conclusions, they write that:
“Optical losses in any spin-photon interface lead to a tremendously reduced efficiency […] This especially holds if an emitter has to repeatedly mediate entanglement for resource states involving hundreds of photons or if quantum memories become involved. Whereas there are most efficient photon detectors with 99.5 % detection efficiency nowadays, equally efficient spin-photon interfaces are still missing. Our system […] enables a spin-photon interface exceeding the needed efficiency of 83 % […] Consequently, we deem the Sawfish cavity design to be critical in interfacing quantum emitters and memories with near-unity efficiencies as required for scalable quantum networks.”
I’ve bold-faced the keyword: ‘efficiency’ because that is a valuable keyword to help you navigate the subfield of quantum memories for tracking the field’s growth. Quantum networks use this gauge of progress frequently.
Storage and Retrieval Efficiency Progress From <10% to 85%
The impressive progress of quantum memories can be seen in comparisons between the first demonstration research ‘Prior Art’ paper, by Gouraud et al. 2015, and the research paper on which the Welinq company is basing their current hardware: Cao et al., 2020 (web site’s: ‘Read more’). In Gouraud et al.’s paper, they write that light pulses are stored in and retrieved with an overall efficiency of (10 ± 0.5) %. In Cao et al.’s work they write that the efficiency reaches (87 ± 5) %. See the plot in the next figure.
Quantum Memory Connects
Quantum Memory sits at the intersection of quantum systems in a quantum value chain which is merging and changing. Currently, the quantum subfields utilized include, but are not limited to, Neutral Atoms, Photonic, Color Centers, and Atomic Vapors. People new to this field might find the following schematic from GQI’s Quantum Technology Introduction presentation helpful.
The Art of Patent Application Filing
The stories in the patent quantum memories record provide more tales. Stories that appeared especially, when comparing those patents in similar fields, which have companies or departments of the same size, and with an academic spin-off origin. Patent writers can learn from each other!
One patent tale pertains to -which- patent office to file? If the EU’s most innovative fund, the EIC, is supporting you, then securing your IPR should be as fast as possible. A decision for World ‘WO’ applicable gives you the most international patent, but ‘WO’ also appears to be slower than other patent offices, for example, the European ‘EP’ office. That’s a lesson from the patent of a quantum memories group in Warsaw, which I’ll describe next time, with more tales.
(*) There are five other GQI presentations that give a status of Quantum Technology sectors in ‘State-of-Play’ Presentations: Quantum Hardware, Quantum Safe, Quantum Sensing, Imaging, and Timing, Quantum Software, Quantum Landscape.
If you are interested to learn more of this Quantum Technology Introduction or any of the Playbooks, please don’t hesitate to contact [email protected].
November 9, 2024
