Q-AMP

​Quantum computers face many bottlenecks towards upscaling the number of qubits and increasing their computational power. One of them is the radio frequency (RF) -bottleneck between the qubit processor inside the cryostat and the room temperature control and readout electronics. And like for their classical counterparts, hope lies in replacing the RF-links by optical fibers, resulting in a hybrid situation where RF-qubits will be used for computation and optical qubits will serve for remote communication. However, electro-optical (EO) devices that parametrically amplify RF-qubits directly to optical qubits and vice versa have thus far remained elusive. Q-Amp will demonstrate a new class of EO-amplifiers that realize the required unity efficiency to achieve this goal. This is impossible with current EO-architectures which suffer from a deleterious trade-off between EO interaction strength (g) and EO losses (Q-factors). This originates from their device design and enhancing g requires bringing the RF-superconducting circuit in close vicinity of the optical waveguide, which comes at the expanse of excess EO losses. To cope with this, we will pioneer a transparent EO device technology that enhances g without the need of bringing superconductors and optical waveguides in close vicinity of each other. We will do so by concentrating the RF- and the optical field in the same nanoscale interaction volume via dipolar screening in ferroelectrics and/or ballistic transport in graphene. Confining both fields within next generation EO-materials will enable an increase of g from 100s of Hz (prior art) to Megahertz-levels. Simultaneously, light is kept away from the lossy superconducting electrodes enabling moderate Q-values of 1E5..1E6. Q-amp’s EO-amplifiers will finally overcome the scaling limitations of current superconducting quantum computers and will provide classical superconducting supercomputers with high-speed EO gateways they desperately need.