0000000000429221

AUTHOR

M. J. Leskinen

showing 4 related works from this author

Quasiparticles, coherence and nonlinearity: exact simulations of RF-spectroscopy of strongly interacting one-dimensional Fermi gases

2008

We consider RF-spectroscopy of ultracold Fermi gases by exact simulations of the many-body state and the coherent dynamics in one dimension. Deviations from the linear response sum rule result are found to suppress the pairing contribution to the RF line shifts. We compare the coherent rotation and quasiparticle descriptions of RF-spectroscopy which are analogous to NMR experiments in superfluid $^3$He and tunneling in solids, respectively. We suggest that RF-spectroscopy in ultracold gases provides an interesting crossover between these descriptions that could be used for studying decoherence in quantum measurement, in the context of many-body quantum states.

PhysicsCondensed Matter::Quantum GasesQuantum decoherenceCondensed matter physicsCondensed Matter - SuperconductivityFOS: Physical sciencesAtomic and Molecular Physics and OpticsSuperfluiditySuperconductivity (cond-mat.supr-con)Condensed Matter - Other Condensed MatterQuantum statePairingQuantum mechanicsQuasiparticleSum rule in quantum mechanicsSpectroscopyCoherence (physics)Other Condensed Matter (cond-mat.other)
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Ultracold atomic Bose and Fermi spinor gases in optical lattices

2006

We investigate magnetic properties of Mott-insulating phases of ultracold Bose and Fermi spinor gases in optical lattices. We consider in particular the F=2 Bose gas, and the F=3/2 and F=5/2 Fermi gases. We derive effective spin Hamiltonians for one and two atoms per site and discuss the possibilities of manipulating the magnetic properties of the system using optical Feshbach resonances. We discuss low temperature quantum phases of a 87Rb gas in the F=2 hyperfine state, as well as possible realizations of high spin Fermi gases with either 6Li or 132Cs atoms in the F=3/2 state, and with 173Yb atoms in the F=5/2 state.

Condensed Matter::Quantum GasesPhysicseinstein condensationSpinorBose gasCondensed matter physicsFOS: Physical sciencesGeneral Physics and Astronomyresonant lightQuantum phasesState (functional analysis)quantum phasesCondensed Matter - Other Condensed Matterground-statesone bosonssystemsddc:530Condensed Matter::Strongly Correlated ElectronsantiferromagnetsDewey Decimal Classification::500 | Naturwissenschaften::530 | PhysikHyperfine structureOther Condensed Matter (cond-mat.other)Spin-½Fermi Gamma-ray Space TelescopeNew Journal of Physics
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Cooper-pair resonances and subgap Coulomb blockade in a superconducting single-electron transistor

2003

We have fabricated and measured superconducting single-electron transistors with Al leads and Nb islands. At bias voltages below the gap of Nb we observe clear signatures of resonant tunneling of Cooper pairs, and of Coulomb blockade of the subgap currents due to linewidth broadening of the energy levels in the superconducting density of states of Nb. The experimental results are in good agreement with numerical simulations.

PhysicsSuperconductivityCondensed matter physicsCondensed Matter - Mesoscale and Nanoscale PhysicsCondensed Matter - SuperconductivityTransistorFOS: Physical sciencesCoulomb blockadeCondensed Matter PhysicsCondensed Matter::Mesoscopic Systems and Quantum Hall EffectElectronic Optical and Magnetic Materialslaw.inventionSuperconductivity (cond-mat.supr-con)Laser linewidthlawCondensed Matter::SuperconductivityMesoscale and Nanoscale Physics (cond-mat.mes-hall)Density of statesCooper pairQuantum tunnellingVoltage
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Pairing based cooling of Fermi gases

2007

We propose a pairing-based method for cooling an atomic Fermi gas. A three component (labels 1, 2, 3) mixture of Fermions is considered where the components 1 and 2 interact and, for instance, form pairs whereas the component 3 is in the normal state. For cooling, the components 2 and 3 are coupled by an electromagnetic field. Since the quasiparticle distributions in the paired and in the normal states are different, the coupling leads to cooling of the normal state even when initially $T_{paired}\geq T_{normal}$ (notation $T_S\geq T_N$). The cooling efficiency is given by the pairing energy and by the linewidth of the coupling field. No superfluidity is required: any type of pairing, or ot…

PhysicsCondensed matter physicsResolved sideband coolingCondensed Matter - SuperconductivityFOS: Physical sciencesCoupling (probability)7. Clean energy01 natural sciencesAtomic and Molecular Physics and Optics010305 fluids & plasmasSuperconductivity (cond-mat.supr-con)Condensed Matter - Other Condensed MatterLaser coolingPairing0103 physical sciencesQuasiparticleAtomic physicsConnection (algebraic framework)010306 general physicsFermi gasEnergy (signal processing)Other Condensed Matter (cond-mat.other)
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