Physical Phenomena in the Ultra-Quantum Regime (UltraQuantum)


The scientific vision of the research initiative UltraQuantum is the complete control of quantum states in solid-state environments. This comprises several implementations of quantum system, like superconductor-ferromagnet heterostructures, ultrasmall magnetic structures and ultrafast magnetization dynamics, spin effects in the ultimately thin material graphene, and the ultrafast manipulation of single electron spins in nitrogen-vacancy centers in diamond. All topics will play an important role in the development of future quantum technologies like ultrafast optoelectronic devices, sensors at the ultimate quantum limit, ultrasmall information storage, or quantum information processing. There are 5 projects:

TP1, Prof. Belzig: We address two fundamental questions of quantum transport in superconductor-ferro­magnet heterostructures. On one hand, the presence of an inhomogeneous magnetization leads to a long-range triplet proximity effect, of which we will investigate to local spectral and the transport properties. This will be done by a solution of the full two-dimensional Usadel equation. On the other hand, we will investigate the non-equilibrium transport properties of spin-dependent atomic contacts under the influence of irradiation and make concrete and quantitative predictions for experiments. Most importantly, the present calculations are in direct connection to experimental efforts in the Scheer group in atomic break junctions with ferromagnetic materials. On the long term, we envisage an intensive collaboration culminating in the simultaneous development of novel spintronic devices and the corresponding theoretical description. Such an effort could play a major role in a future research initiative on non-equilibrium quantum phenomena in solid-state devices.

TP5, Prof. Scheer: In this experimental project we will address fundamental questions of quantum transport in nanostructures consisting of ferromagnets in contact with either normal metals or super­conductors. At the interfaces of those heterostructures novel quantum states form which extend over length scales of a few nanometers up to a few micrometers. Since the energy scales, which are relevant for the formation of these new quantum states, correspond to frequencies of the order of gigahertz to terahertz, we will study how the transport properties of such structures can be tuned by irradiation with electromagnetic fields in this frequency range.

  • Department of Physics
  • WG Nowak (Theoretische Physik mit SP Moderne Materialeigenschaften)
  • WG Burkard (Theoretische Physik mit SP Festkörperphysik und Quanteninformation)
  • WG Belzig (Theoretische Physik mit SP Quantentransport)
  • WG Leitenstorfer (Experimentalphysik mit SP Ultrakurzzeitphysik und Quantenoptik)
  • WG Scheer (Experimentalphysik mit SP Nanoelektronik)
  • Zukunftskolleg
Funding sources
Name Finanzierungstyp Kategorie Project no.
Exzellenzinitiative third-party funds research funding program 401/10
Further information
Period: 15.01.2010 – 31.10.2012