Quantum transport in nanostructures
- Submicron size scale technology in the electronic devices opened the possibility to investigate quantum coherence and electron-electron effects on the transport properties in novel and controlled geometries. Using semiconductor heterostructures very narrow electronic channels can be studied with tunable electron density. By using a lateral confinement scheme, the width of the channel can also be changed. This makes experimentally accessible the creation of one and zero dimensional (1D-0D) electronic systems, i.e. quantum wire and quantum dots. Classical transport here breaks down due to discretization of the energy spectrum, quantum interference and electron-electron interaction.
Superconductivity, Josephson junction arrays, superconducting nanocircuits
- Mesoscopic superconductivity has been at the centre of the attention of theorists and experimentalist since several decades. The realization of arrays of small Josephson junctions (the first example of what we would define now a quantum simulator) allowed to study of whealth of phenomena ranging from quantum phase transitions to the quantum dynamics of vortices. More recently superconducting nanocircuits have become among the most promising implementations for quantum information processing. Furthermore quantum transport in hibrid (normal metal - superconducting) systems has received revived interest because of the possibility to realise Majorana edge modes.
Quantum simulators (Cold atoms in optical lattices, QED-arrays)
- Artificial many-body systems can be also important tools to simulate other quantum systems, quantum simulators especially when interactions are strong and available analytical and numerical tools have limited power. Crucial for all these applications is the ability to manipulate many-body systems in a controlled fashion. At present cold atoms in optical lattices and trapped ions are the most promising implementations bringing together atomic and molecular physics with condensed matter. Remarkable progresses in tayloring light-matter interaction has however entered a regime in which very strong effective photon-photon interactions could be realized fueling, in the last few years, an increasing interest towards the realization of quantum simulators with strongly interacting photons.
Non-equilibrium dynamics of many-body systems
- Triggered by the impressive progress of experiments on ultracold atomic gases, where both the initial state and the Hamiltonian dynamics can be engineered with unprecedented accuracy, there has been a burst in the understanding of the non-equilibrium dynamics of quantum many-body closed systems.
Quantum information processing (entanglement in many-body systems, tensor networks, solid state implementations)
- Over the years, there has been a rapid down-scaling in classical logic devices which has lead to an enormous increase of the computer performance. The recent discovery of new principles of computation based on quantum mechanics has opened up new perspectives. The quantum nonlocality of entangled states can be used for novel forms of information processing, such as quantum cryptography, quantum teleportation, and superfast quantum computations. In addition the more recently it has become clear that the cross-fertiliaztion between quantum information and condensed matter would lead to additional understanding of many-body systems.
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