Short TeraHertz electrical pulses for the generation of flying Qubits – STEPforQubits

The STEPforQubits project aims to design and fabricate semiconductor devices for the high efficiency conversion of optical pulses into electrical pulses for applications in quantum technology. These devices based on nanophotonics and plasmonics concepts will generate pulses with a duration of 2 ps and an amplitude of 100 mV, for optical control energies of less than 1 pJ per pulse and a supply voltage of 1 V. They will be integrated with an electronic circuit (2D electron gas) with quantum properties that allows the coherent propagation of flying Qubits. Such an association of THz optoelectronic circuits with quantum electronic circuits offer a unique opportunity to develop a new technological platform for quantum technology and applications. The short duration of the electrical pulses, less than the time of flight in the circuit, will allow us to observe "in real time" the quantum interferences between an electronic pulse and the Fermi Sea. We will then demonstrate new quantum electronics functionalities that can be used to perform basic quantum computation operations. For example, we will demonstrate the possible manipulation over time and on a picosecond scale of a superposition of quantum states through the dynamic control of a potential barrier driven by a picosecond voltage pulse. The perfect demonstration of this experiment requires electrical pulses of amplitude and duration generated "on demand". In this project, we therefore plan to also address the generation of such signals, by creating an optoelectronic circuit specially dedicated to this function.