Maslov Gainesville , and Daniel Loss. Thermal stability is achieved by weakly coupling the qubits to additional cavity modes that mediate long-range attractive interactions between the stabilizer operators of the toric code. Appropriately defining the thermal conductance for bosons, we find that the magnon Hall conductances get quantized and show a universal thermomagnetic behavior, i. At the same time, the university has positioned itself amidst the international competition in the form of five strategic focal areas: life sciences, visual studies, nanosciences, sustainability and energy research and european and global studies. We present a scalable hybrid architecture for the 2D surface code combining superconducting resonators and hole-spin qubits in nanowires with tunable direct Rashba spin-orbit coupling. Overall, we find that in a sufficiently long edge the nuclear spins, whether ordered or not, suppress the edge conductance to zero as the temperature approaches zero. We find again that the interaction drives the system into the topological phase and, as the strength of the source term coming from the tunneling Hamiltonian increases, strong electron-electron interactions are required to reach the topological phase.
Here, we use this fact to control the flow of a spin current through the molecular magnet by electric- or magnetic means. Second Order Topological Superconductivity in pi-Junction Rashba Layers Yanick Volpez, Daniel Loss, and Jelena Klinovaja We consider a Josephson junction bilayer consisting of two tunnel-coupled two-dimensional electron gas layers with Rashba spin-orbit interaction, proximitized by a top and bottom s-wave superconductor with phase difference phi close to pi. This allows one to determine the topological phase of the Rashba nanowire independently of the presence of Majorana bound states. Marc Nicolas Sommer Basel : Das Konzept ein. This provides a connection between low-dimensional magnetism and non-analyticities in interacting 2D electron systems. Reeg, Jelena Klinovaja, and Daniel Loss ;.
In 1996 he returned to Switzerland to become full Professor of Theoretical Physics at the University of Basel. We theoretically discover that magnon transport in junctions has a universal behavior, i. We also choose a specific anyon model and error model to probe the problem in more detail. We present the software library libCreme which we have previously used to successfully calculate convex-roof entanglement measures of mixed quantum states appearing in realistic physical systems. For fractional wires, we find that the low energy tunneling density of states vanishes.
The nuclear spin helix opens a temperature-dependent partial gap in the electron spectrum. We next propose how to control the direct-current dc Josephson effect electrically using the A-C phase, which is the geometric phase acquired by magnons moving in an electric field. Coish Waterloo , Jan Fischer, and Daniel Loss. This paves the way to realizing spin filter devices in graphene nanoribbons in the temperature regime of a few Kelvins. To use quantum systems for technological applications we first need to preserve their coherence for macroscopic timescales, even at finite temperature.
We confirm aforementioned results by considering a more microscopic approach which starts from the tunneling Hamiltonian between the three-dimensional s-wave superconductor and the nanowires. Within the Hubbard model, we find a relation between the spin-electric coupling and the properties of the chemical bonds in a molecule, suggesting that the best candidates for strong spin-electric coupling are molecules with nearly degenerate bond orbitals. We show that a large band shift is induced in the semiconductor by the superconductor in this geometry, thus making it challenging to realize a topological phase. Motivated by possible applications in spintronics, we consider rectification effects in both ferromagnetic and antiferromagnetic systems. In particular, we find an efficient spin transmission through the magnetic region of a characteristic resonant length, which can be related to the properties of the boundary Majorana zero modes. Dynamic Generation of Topologically Protected Self-Correcting Quantum Memory Daniel Becker, Tetsufumi Tanamoto Toshiba , Adrian Hutter, Fabio L.
Guided by recent advances in surface codes, we also consider the perpendicular geometry. He is married and has two sons. Hierbei stehen zwei Dinge im Fokus: Zum einen soll die Präsenz der Basler Musikwissenschaft in Moskau den kulturellen Austausch und die wissenschaftliche Diskussion zwischen Basel und Moskau fördern und Perspektiven für weiterführende Lern- und Forschungsaktivitäten eröffnen. Here we find additional effects, namely the crossing and the anti-crossing of spin-split levels depending on subband index and magnetic field direction. It exploits a long-lived metastable charge state, which increases both the contrast and the duration of the charge signal distinguishing the two measurement outcomes. The first quantum pump setup consists of a charge-density-modulated quantum wire, and the second one is based on a semiconducting nanowire with Rashba spin-orbit interaction, in the presence of a spatially oscillating magnetic field.
Leuenberger Orlando , Daniel Loss, and J. The difference depends on the Fermi occupation factor and the spin relaxation becomes slower when the energy level of the quantum dot is lowered. In a microscopic quantum field theory approach we include the unavoidable coupling of the external field to the magnons, which gives rise to time-dependent dissipation for the skyrmion. We propose the use of a superconducting trijunction to realize non-Abelian statistics of such Majorana bound states. Majorana qubit decoherence by quasiparticle poisoning Diego Rainis and Daniel Loss.
Sie ist im Rahmen einer Lehrveranstaltung für Studierende aller Semesterstufen in zwei Teilen im Herbstsemester 2010 und im Frühjahrssemester 2011 durchgeführt worden. We further calculate the spin susceptibility also at finite frequencies and thereby obtain the spin noise in real space via the fluctuation-dissipation theorem. Promoting the center of the Skyrmion to a dynamic quantity, the fluctuations around the Skyrmionic configuration give rise to a time-dependent damping of the Skyrmion motion. The bilayer setup consists of an s-wave superconductor sandwiched between two two-dimensional electron gas layers with strong Rashba spin-orbit interaction. Fractional Charge and Spin States in Topological Insulator Constrictions Jelena Klinovaja and Daniel Loss. Furthermore, we present perturbative gadgets for generating the required five-spin operators. Hachiya, Daniel Loss, and J.
What is the electrical conductance of such a quantum wire? Magnetically-Defined Qubits on 3D Topological Insulators Gerson J. In both these quantum pumps transport is investigated in a N-X-N geometry, with the system of interest X connected to two normal-metal leads N , and the two pumping parameters are the strengths of the effective wire-lead barriers. The model consists of an infinite strip of finite width that contains periodically arranged stripes forming supercells to which the electrons are confined and between which they can hop with associated magnetic phases. We demonstrate a controlled-phase gate that acts within 5. This is a very relevant question since so far no clear experimental observation in that direction has been produced.