Fall 2018

Interfaces between two distinct complex oxide materials can display ground states which diverge greatly from the parent compounds, making them a playground to establish emergent phenomena. Particularly intriguing are the so-called polar interfaces where a diverging electrostatic potential leads to charge transfer. The canonical polar interface between two insulating oxides, LaAlO3/SrTiO3, forms a two-dimensional electron liquid which superconductors at low-temperature and where the conductivity can be manipulated by changing the film surface. Here, I will demonstrate novel functionality at...

Preserving the quantum coherence of signals is of paramount importance for components utilized in quantum information processing, quantum computation and quantum measurement setups. In recent years a tremendous progress has been made in the development of quantum-limited components, such as reciprocal and nonreciprocal amplifiers, circulators and isolators. A promising way to design these devices is based on parametric modulation of coupled modes, where the required mode-mixing processes are realized by utilizing Josphson junction-based tunable couplers or via coupling to mechanical...

Schedule:

Morning Session Chair: Sergey Frolov, University of Pittsburgh

9:00 Benjamin Hunt, Carnegie Mellon University Tuning Ising Superconductivity with Layer and Spin-Orbit Coupling in 2D Transition-Metal Dichalcogenide Superconductors

9:40 Javad Shabani, New York University Josephson junctions in two-dimensional epitaxial Al-InAs structures

10:20 Coffee Break

10:50 Leonid Glazman, Yale University Demkov-Osherov tunneling of Majorana fermions

11:30 Julia Meyer, CEA Saclay Spontaneous spin polarization of non-equilibrium...

Schedule:

Morning Session Chair: Michael Hatridge, University of Pittsburgh

9:00 Manuel Houzet, CEA Grenoble Microwave spectroscopy of a weakly-pinned charge density wave in a Josephson junction chain

9:40 Erik Bakkers, TU Eindhoven Bottom-up grown nanowire quantum devices

10:20 Coffee Break

10:50 Michel Devoret, Yale University Addressing spectroscopically single Andreev levels in super-semi nanowires

11:30 Peter Krogstrup, Microsoft Quantum and Niels Bohr Institute Hybrid epitaxy of magnetic-semiconductor-superconductor materials...

Schedule:

Morning Session Chair: Victor Vakaryuk, Physical Review

9:00 Chris Palmstrøm, UCSB

9:40 Barbara Jones, IBM. The Keldysh-ETH quantum computation algorithm

10:20 Coffee Break

10:50 Philip Kim, Harvard University. Interlayer Excitons and Magneto-Exciton Condensation in van der Waals Heterostructures

11:30 Andrei Bernevig, Princeton. Topology of Twisted Graphene from Topological Quantum Chemistry

12:10 Lunch Break

Afternoon Session Chair: Benjamin Hunt, Carnegie Mellon University

2:00 Andrea Young, UCSB....

Majorana fermions are non-trivial quantum excitations that have remarkable topological properties and can be used to protect quantum information against decoherence. Tunneling spectroscopy measurements on one-dimensional superconducting hybrid materials have revealed signatures of Majorana fermions which are the edge states of a bulk topological superconducting phase. We couple strong spin-orbit semiconductor InSb nanowires to conventional superconductors (NbTiN, Al) to obtain additional signatures of Majorana fermions and to explore the  topological phase transition. A potent alternative explanation for many of the recent experimental Majorana reports is that a non-topological Andreev state localizes near the end of a nanowire. We compare Andreev and Majorana modes and investigate ways to clearly distinguish the two phenomena. We are also exploring how Andreev states can be chained together along the nanowire to realize the one-dimensional Kitaev model, a discrete way of generating Majorana modes.