SUPERDYN · Extreme nonlinear dynamics of driven superconductors
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2020-12-15 → 2022-12-14
- EU contribution
- €183,473
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Extreme nonlinear dynamics of driven superconductors
Superconductivity is a fascinating state of matter in which the electrons flow without any resistance inside a material. This phenomenon occurs at very low temperatures and constitutes an unique manifestation of quantum physics at macroscopic scale in which electrons form Copper pairs (bosons) that can condensate. Superconductors (the materials in which the superconductivity phenomenon takes place) are being used nowadays to build several quantum technologies and one of the reasons is the rather long time during which they can maintain their quantum mechanical properties (coherence time). This particular property also opens the door to explore new nonequilibrium phenomena occurring at short times before the environment effect and/or residual interactions make the system thermalise. One of the main goals of SUPERDYN was to study and manipulate new non equilibrium and transient responses of superconductors when they are excited by light pulses or other periodic drives. W noe obtained a complete and very rich phase diagram for periodically driven superconductors which demonstrated the possibility to design and engineer new phases of matter in the time domain in this kind of materials. We identified four different dynamical behaviours including time crystals, synchronized Higgs modes, Rabi-Higgs oscillations and very ordered gapless phases depending on the drive parameters. We also significantly advanced in understanding the origin of these phases and the emergence of parametric resonances that we found, which could have potential application in parametric amplification, frequency converters and improved quantum sensing. We also have shed light on the origin of different Higgs amplitude modes in superconductors not necessarily associated with spontaneous symmetry breaking but with singularities in the spectrum of the system. In this case we demonstrated that by engineering the lattice in which the electrons can move and the type of excitation acting on the system it is possible to stabilise new Higgs oscillations on demand constituting an example of control and manipulation of superconducting properties.
Data: CORDIS, © European Union
Project objective
Due to very long energy relaxation times and strong non-linearities superconductors are the workhorse of many solid state quantum technologies. Previous studies have shown that a periodically excited superconductor can be taken to a new highly-nonlinear regime where quasiparticles perform synchronous collective Rabi oscillations. SUPERDYN will address all the challenges to observe these and similar highly nonlinear states in experiments. In particular, we will analyse thermalization process beyond a mean-field dynamics i.e. taking into account the effect of the environment, residual interactions and disorder. Results obtained with non-equilibrium diagrammatic techniques (Keldysh) will be validated comparing with computations within non-equilibrium dynamical mean-field theory (DMFT). Both the transient nonlinearities and the steady-state nonlinearities will be studied. In the latter case we expect typical effects of nonlinear quantum optics as induced transparency. A microwave device will be designed to measure these effects. This will require developing beyond state-of-the-art software and techniques to treat quasiparticle excitations and low-energy plasma modes on an equal footing. We will also develop a new variational method to obtain optimum driving protocols to obtain a desired transient superconducting state. The project will benefit from the synergies with various experimental groups. Secondments in a leading DMFT group and a leading experimental group developing quantum devices will complement the formation. The Experienced Researcher will be taken to a leadership position in the field of nonequilibrium superconductivity and solid-state quantum technologies with excellent future career prospects.
Original text from CORDIS.
Participants
- CONSIGLIO NAZIONALE DELLE RICERCHE · RomaCoordinatorItaly
Links
Data: CORDIS, © European Union