WP1: 2D-materials growth & nanostructuring are essential for the progress of Quantum Electronics. Graphene can easily be affected by its surrounding environment, leading to a degradation of properties. Several strategies will be followed. h-BN will be grown as a substrate suitable for improved graphene properties. The ballistic nature of room-temperature transport in Graphene nanoribbons on SiC will be studied. As for electron beam lithography, we will tackle the gap between the purely technological development and its practical implementation. We will develop new methods for a novel high-resolution resist, a double-layer resist for multiple angle evaporation and the local patterning by beam-induced deposition.
WP2: Quantum thermodynamics is an emerging area of research in Quantum Electronics. In the quantum limit, thermodynamics can yield a complete characterisation of the energy balance of a nanocircuit connected to its environment in terms of free energy, work and heat. Superconducting and semiconducting qubits are an important starting point, as these systems are described by simple Hamiltonians and offer very stable operation conditions that permit very large statistical ensembles through electron counting. A nanocalorimeter for detecting single microwave photons emitted by a superconducting qubit and a quantum refrigerator based on a superconducting transmon qubit will be constructed. A related theoretical effort will build a conceptual framework for quantum heat detectors and also target a deeper understanding of the behaviour of thermal radiation in the near-field. Electronic cooling and thermoelectric effects will be investigated in a quantum dot-based single electron transistor.
WP3: Spintronics controlled by spin-orbit interactions. Materials with low spin-orbit interactions give rise to long spin coherence times, whereas strong spin-orbit interactions lead to inter-conversion between charge and spin currents. More efficient versions of old devices or entirely new functionalities are made possible. The goal of this WP is demonstrating three different examples of this: low spin-orbit organic spin hot-electron transistors and spin-photovoltaic cells with optimised spin relaxation time, spin-charge inter-conversion at interfaces with a strong Rashba spin-orbit coupling, and Quantum Spin Hall Effect in coupled semiconductor quantum wells.
WP4: Electron transport in reduced dimensionality is a key for the development of novel purely electronic device concepts without making use of the electron spin. In this WP, we will explore novel transport phenomena based on electronic interactions fostered by the low dimension and unconventional combinations of constituents. The aim is to address fundamental questions of electronic states of matter, as well as to point out those transport effects that might be applicable for future devices. The systems under study are either one-dimensional (1D, graphene nanoribbons) or zero-dimensional (individual metallic or superconducting nanoparticles, molecules acting as quantum dots). 1D electronic states offer possibilities of ballistic and gate-tuneable electronic transport. Quantum dots implement two- or few-level systems with energy scales suitable for room-temperature operation.