ORQUID - ORganic QUantum Integrated Devices

Our society relies on secure communication, powerful computers and precise sensors. Basic science has shown that huge improvements in these capabilities are possible if we can utilise many single quantum objects working in concert. We can then see how to store and process huge amounts of information in a fully secure way and how to make exquisitely sensitive measurements of fields and forces. Specific types of quanta - photons, electrons, phonons - already bring new specific functions, but to realise the full promise of quantum technologies, it will be necessary to interface these systems with each other in a way that is practical and scalable. This is the focus of our programme.

ORQUID will explore the exciting new possibility of using single organic molecules as the interface between these three quanta so that they can work together as required. First, single molecules will interact with light in waveguides and cavities to generate and detect single photons, providing immediate impact in quantum photonics. Second, single molecules will detect single moving charges in nano-electronic circuits to provide quantum coherent information exchange between these charges and the external world. Third, molecules embedded in nanomechanical devices and two-dimensional materials will measure nanoscale forces and displacements, which are key to developing mechanical quantum systems and understanding nano-machinery. By developing these three interfaces on a common platform, we will create a versatile hybrid system. By allowing the user to draw simultaneously on the most sensitive quantum aspects of light, charge and sound, we anticipate that this hybrid will be a major advance in the technology of quantum devices.

In the spirit of QuantERA, the ORQUID consortium will "explore collaborative advanced multidisciplinary science...with the potential to initiate or foster new lines of quantum technologies and help Europe grasp leadership early on in promising future technology areas." ORQUID aligns with a number of the target outcomes of QuantERA. (i) Quantum Communications. Our programme will deliver "Novel photonic sources for quantum information and quantum communication" - specifically a chip containing 8 molecules acting as fast sources of identical photons. We will also deliver "Coherent transduction of quantum states between different physical systems" by using molecules to convert quantum information from electrons to photons. Both these elements of ORQUID fall under the umbrella of "Integrated quantum photonics." (ii) Quantum Computing. Our photon sources will also contribute to "devices to realise multi-qubit algorithms", as will the use of single molecules to make a strong nonlinearity that can mediate a photon-photon interaction. (iii) Quantum Information Science. We will use molecules and quantum interference to demonstrate "Novel sources of non-classical states and methods to engineer such states." Finally, in (iv) Quantum Sensing, our use of molecules to sense displacement, fundamental forces, charge, and phase will fit well with the demands for "Development of detection schemes that are optimised with respect to extracting relevant information from physical systems" and "Implementation of micro- and nano- quantum sensors."

ORQUID will have far-reaching impact on society through enlightening researchers on the use of organic emitters in inorganic devices, and through the myriad applications this provides. Some specific impact areas are:

Providing a deeper understanding of solid-state quantum systems: It is almost certain that practical advances in quantum technology now require a strong push to develop solid state systems and to understand much more deeply how electrons, photons and quantum emitters interact with each other in that environment. Our programme addresses that need and will provide a strong practical basis on which to develop next-generation quantum devices.

Enhancing interdisciplinarity to enlarge the community involved in tackling these new challenges: ORQUID will focus on organic molecules integrated in planar semiconductor technology, bringing a strong involvement of the organic chemistry community (CNRS, IFPAN), the nanofabrication community (WWU), the 2D materials community (ICFO), the quantum optics community (IMP, CNR) and single molecule experts (LEI), promoting novel original solutions to grand challenges in modern quantum science.

Developing reliable technologies for different components of quantum architectures: In the short term, the main impact of our programme is likely to flow from the specific devices we build which include:

1. An array of 8 single photon sources which will be immediately relevant for secure communications using quantum cryptography protocols, for algorithms based on linear optical quantum computing, and for quantum simulation where problems intractable for classical computing hardware can be solved.

2. Nonlinear single photon transistors, switches and phase shifters. This capability opens a number of avenues to build novel quantum technology, including use in a universal quantum controlled-NOT gate, a building block for a future quantum computer.

3. A quantum non-demolition single-charge detector will provide an optical, contact-free reading of charge state, with better signal-to-noise ratio, lower shot noise and better linearity than current technology. Our new platform will miniaturize the electronics-optics interface while showing quantum capabilities.

4. An ultra-sensitive nanoscale displacement detector will deepen our understanding of nanoscale machines and improve on current technology for sensing motion. This will be a significant advance for optomechanics.

By building on the existing technology of integrated optics, and extending it beyond the regime of pure quantum photonics, we aim for a generic platform where electronics, optics, and mechanics can all be linked to provide a framework for building practical quantum devices.

Technology is moving to ever smaller structures and architectures. IBM recently offered a 5 nm transistor system - close to the limit set by the size of atoms. To go further, technology must work at the individual particle level, where quantum behaviour can be a valuable resource. Our research on controlling single quanta will give access to that resource and provide a basis for achieving exponentially faster computing, fully secure communications and unparalleled sensing capabilities. Clearly any one of these has the potential for major social impact. The new approaches and capabilities that emerge from the detection and the controlled interaction between single particles of light, matter and charge will bring a step change in the power of sensing, communications and information processing devices. The importance of this proposal lies in the tremendous promise of single molecules for quantum technologies; whilst being affordable, when combined with established nanophotonic, nanoelectronic and optomechanical components, they offer single-particle sensitivity, flexibility, and scalability.