ultracold atoms; nanomechanics; quantum coherence; condensed-matter theory; mesoscopic superconductivity
Lode A.U.J., Bruder C. (2017), Fragmented superradiance of a Bose-Einstein condensate in an optical cavity, in Phys. Rev. Lett.
, 118, 013603-013603.
Pedder Christopher J., Meng Tobias, Tiwari Rakesh P., Schmidt Thomas L. (2017), Missing Shapiro steps and the 8 pi-periodic Josephson effect in interacting helical electron systems, in PHYSICAL REVIEW B
, 96(16), 165429.
Weiner S.E., Tsatsos M.C., Cederbaum L.S., Lode A.U.J. (2017), Phantom vortices: hidden angular momentum in ultracold dilute Bose-Einstein condensates, in Sci. Rep.
, 7, 40122-40122.
Lörch N., Nigg S.E., Nunnenkamp A., Tiwari R.P., Bruder C. (2017), Quantum synchronization blockade: Energy quantization hinders synchronization of identical oscillators, in Phys. Rev. Lett.
, 118, 243602-243602.
Nigg S.E., Lörch N., Tiwari R.P. (2017), Robust quantum optimizer with full connectivity, in Sci. Adv.
, 3, 1602273-1602273.
Sekera T., Bruder C., Mele E. J., Tiwari R. P. (2017), Switchable valley filter based on a graphene p-n junction in a magnetic field, in PHYSICAL REVIEW B
, 95(20), 205431.
Amitai E., Lörch N., Nunnenkamp A., Walter S., Bruder C. (2017), Synchronization of an optomechanical system to an external drive, in Phys. Rev. A
, 95, 053858-053858.
Huembeli P., Nigg S.E. (2017), Towards a heralded eigenstate-preserving measurement of multi-qubit parity in circuit QED, in Phys. Rev. A
, 96, 012313-012313.
Pedder Christopher J., Meng Tobias, Tiwari Rakesh P., Schmidt Thomas L. (2016), Dynamic response functions and helical gaps in interacting Rashba nanowires with and without magnetic fields, in PHYSICAL REVIEW B
, 94(24), 245414.
Lode Axel U. J., Bruder Christoph (2016), Dynamics of Hubbard Hamiltonians with the multiconfigurational time-dependent Hartree method for indistinguishable particles, in PHYSICAL REVIEW A
, 94(1), 013616.
Lörch Niels, Amitai Ehud, Nunnenkamp Andreas, Bruder Christoph (2016), Genuine Quantum Signatures in Synchronization of Anharmonic Self-Oscillators, in PHYSICAL REVIEW LETTERS
, 117(7), 073601.
Zyuzin A. A., Tiwari R. P. (2016), Intrinsic Anomalous Hall Effect in Type-II Weyl Semimetals, in JETP LETTERS
, 103(11), 717-722.
Lode Axel U. J. (2016), Multiconfigurational time-dependent Hartree method for bosons with internal degrees of freedom: Theory and composite fragmentation of multicomponent Bose-Einstein condensates, in PHYSICAL REVIEW A
, 93(6), 063601.
Fasshauer Elke, Lode Axel U. J. (2016), Multiconfigurational time-dependent Hartree method for fermions: Implementation, exactness, and few-fermion tunneling to open space, in PHYSICAL REVIEW A
, 93(3), 033635.
Amitai Ehud, Tiwari Rakesh P., Walter Stefan, Schmidt Thomas L., Nigg Simon E. (2016), Nonlocal quantum state engineering with the Cooper pair splitter beyond the Coulomb blockade regime, in PHYSICAL REVIEW B
, 93(7), 075421.
Grimm M., Bruder C., Lörch N. (2016), Optomechanical self-oscillations in an anharmonic potential: engineering a nonclassical steady state, in J. of Optics
, 18, 094004-094004.
Orth Christoph P., Sekera Tibor, Bruder Christoph, Schmidt Thomas L. (2016), The topological Anderson insulator phase in the Kane-Mele model, in SCIENTIFIC REPORTS
, 6, 24007.
Sekera Tibor, Bruder Christoph, Belzig Wolfgang (2016), Thermoelectricity in a junction between interacting cold atomic Fermi gasese, in PHYSICAL REVIEW A
, 94(3), 033618.
Nigg Simon E., Tiwari Rakesh P., Walter Stefan, Schmidt Thomas L. (2015), Detecting nonlocal Cooper pair entanglement by optical Bell inequality violation, in PHYSICAL REVIEW B
, 91(9), 094516.
Strübi Gregory, Belzig Wolfgang, Schmidt Thomas L., Bruder Christoph (2015), Full counting statistics of Majorana interferometers, in PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
, 74, 489-495.
Sothmann Bjoern, Tiwari Rakesh P. (2015), Josephson response of a conventional and a noncentrosymmetric superconductor coupled via a double quantum dot, in PHYSICAL REVIEW B
, 92(1), 014504.
Orth Christoph P., Tiwari Rakesh P., Meng Tobias, Schmidt Thomas L. (2015), Non-Abelian parafermions in time-reversal-invariant interacting helical systems, in PHYSICAL REVIEW B
, 91(8), 081406.
Liu Yang, Tiwari Rakesh P., Brada Matej, Bruder C., Kusmartsev F. V., Mele E. J. (2015), Snake states and their symmetries in graphene, in Phys. Rev. B
, 92, 235438-235438.
Tiwari Rakesh P., Zülicke U., Bruder C., Stojanovic Vladimir M. (2014), Neutral edge modes in a superconductor-topological-insulator hybrid structure in a perpendicular magnetic field, in EPL
, 108(1), 17009.
A. Quantum coherence and statistics of mesoscopic systems:To access finite-frequency noise is experimentally difficult, since it requires a precise control of the measurement circuit at high frequencies. We will study the perspectives of a suspended nanomechanical device as a detector of frequency-dependent quantum noise. Motivated by recent breakthrough transport experiments with ultracold neutral atoms, we will also investigate theoretical proposals related to this setup, like time-dependent transport, drag experiments, noise and cross-correlation experiments. We would like to understand whether it is possible to do experiments known from non-equilibrium superconductivity (like charge imbalance or an enhancement of the superconducting orderparameter) by creating a non-equilibrium distribution of quasiparticles. Finally, we will find memory functions corresponding to particular operator orderings in a physical measurement setup.B. Mesoscopic superconductivity:We will calculate the full counting statistics (FCS) of interferometric structures that have arms containing Majorana quasiparticles and will link our results to recent FCS work that was related to localized Majorana excitations. In addition, we will show that a superconducting beam splitter embedded in a microwave cavity can be used to obtain information about the bulk order parameter of unconventional and non-centrosymmetric superconductors. Finally, we will study systems with a small number of superconducting qubits. For interacting quantum bits, external control of a single qubit may be sufficient to generate an arbitrary unitary transformations on a multi-qubit system. We will apply this idea to asimple bit-flip error correction algorithm that can be implemented as a unitary gate on a 5-qubit system.