The Experts below are selected from a list of 1338 Experts worldwide ranked by ideXlab platform
G K Campbell - One of the best experts on this subject based on the ideXlab platform.
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Superflow in a toroidal bose einstein condensate an atom circuit with a tunable weak link
Physical Review Letters, 2011Co-Authors: Anand Ramanathan, Kevin Wright, C J Lobb, William D Phillips, S R Muniz, Martin Zelan, W T Hill, Kristian Helmerson, G K CampbellAbstract:We have created a long-lived ({approx_equal}40 s) persistent current in a toroidal Bose-Einstein condensate held in an all-optical trap. A repulsive optical barrier across one side of the torus creates a tunable weak link in the condensate circuit, which can affect the current around the loop. Superflow stops abruptly at a barrier strength such that the local flow velocity at the barrier exceeds a critical velocity. The measured critical velocity is consistent with dissipation due to the creation of vortex-antivortex pairs. This system is the first realization of an elementary closed-loop atom circuit.
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Superflow in a toroidal bose einstein condensate an atom circuit with a tunable weak link
Physical Review Letters, 2011Co-Authors: Anand Ramanathan, Kevin Wright, C J Lobb, William D Phillips, S R Muniz, Martin Zelan, W T Hill, Kristian Helmerson, G K CampbellAbstract:We have created a long-lived ($\ensuremath{\approx}40\text{ }\text{ }\mathrm{s}$) persistent current in a toroidal Bose-Einstein condensate held in an all-optical trap. A repulsive optical barrier across one side of the torus creates a tunable weak link in the condensate circuit, which can affect the current around the loop. Superflow stops abruptly at a barrier strength such that the local flow velocity at the barrier exceeds a critical velocity. The measured critical velocity is consistent with dissipation due to the creation of vortex-antivortex pairs. This system is the first realization of an elementary closed-loop atom circuit.
Zoran Hadzibabic - One of the best experts on this subject based on the ideXlab platform.
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quantized supercurrent decay in an annular bose einstein condensate
Physical Review A, 2012Co-Authors: Stuart Moulder, Scott Beattie, Robert P Smith, Naaman Tammuz, Zoran HadzibabicAbstract:We study the metastability and decay of multiply-charged Superflow in a ring-shaped atomic Bose-Einstein condensate. Supercurrent corresponding to a giant vortex with topological charge up to q=10 is phase-imprinted optically and detected both interferometrically and kinematically. We observe q=3 Superflow persisting for up to a minute and clearly resolve a cascade of quantised steps in its decay. These stochastic decay events, associated with vortex-induced $2 \pi$ phase slips, correspond to collective jumps of atoms between discrete q values. We demonstrate the ability to detect quantised rotational states with > 99 % fidelity, which allows a detailed quantitative study of time-resolved phase-slip dynamics. We find that the supercurrent decays rapidly if the Superflow speed exceeds a critical velocity in good agreement with numerical simulations, and we also observe rare stochastic phase slips for Superflow speeds below the critical velocity.
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quantized supercurrent decay in an annular bose einstein condensate
Physical Review A, 2012Co-Authors: Stuart Moulder, Scott Beattie, Robert P Smith, Naaman Tammuz, Zoran HadzibabicAbstract:We study the metastability and decay of multiply-charged Superflow in a ring-shaped atomic Bose-Einstein condensate. Supercurrent corresponding to a giant vortex with topological charge up to q=10 is phase-imprinted optically and detected both interferometrically and kinematically. We observe q=3 Superflow persisting for up to a minute and clearly resolve a cascade of quantised steps in its decay. These stochastic decay events, associated with vortex-induced $2 \pi$ phase slips, correspond to collective jumps of atoms between discrete q values. We demonstrate the ability to detect quantised rotational states with > 99 % fidelity, which allows a detailed quantitative study of time-resolved phase-slip dynamics. We find that the supercurrent decays rapidly if the Superflow speed exceeds a critical velocity in good agreement with numerical simulations, and we also observe rare stochastic phase slips for Superflow speeds below the critical velocity.
Aurel Bulgac - One of the best experts on this subject based on the ideXlab platform.
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time dependent density functional theory and the real time dynamics of fermi superfluids
Annual Review of Nuclear and Particle Science, 2013Co-Authors: Aurel BulgacAbstract:I describe the time-dependent superfluid local density approximation, which is an adiabatic extension of the density functional theory to superfluid Fermi systems and their real-time dynamics. This new theoretical framework has been used to describe several phenomena in cold atomic gases and nuclear collective motion: excitation of the Higgs modes in strongly interacting Fermi superfluids, generation of quantized vortices, crossing and reconnection of vortices, excitation of the Superflow at velocities above the critical velocity, excitation of quantum shock waves and domain walls in the collisions of superfluid atomic clouds, and excitation of collective states in nuclei.
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time dependent density functional theory and the real time dynamics of fermi superfluids
arXiv: Quantum Gases, 2013Co-Authors: Aurel BulgacAbstract:I describe the Time-Dependent Superfluid Local Density Approximation, which is an adiabatic extension of the Density Functional Theory to superfluid Fermi systems and their real-time dynamics. This new theoretical framework has been applied to describe a number of phenomena in cold atomic gases and nuclear collective motion: excitation of the Higgs modes in strongly interacting Fermi superfluids, generation of quantized vortices, crossing and reconnection of vortices, excitation of the Superflow at velocities above the critical velocity, excitation of quantum shock waves and domain walls in the collisions of superfluid atomic clouds, excitation of collective states in nuclei.
Anand Ramanathan - One of the best experts on this subject based on the ideXlab platform.
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Superflow in a toroidal bose einstein condensate an atom circuit with a tunable weak link
Physical Review Letters, 2011Co-Authors: Anand Ramanathan, Kevin Wright, C J Lobb, William D Phillips, S R Muniz, Martin Zelan, W T Hill, Kristian Helmerson, G K CampbellAbstract:We have created a long-lived ({approx_equal}40 s) persistent current in a toroidal Bose-Einstein condensate held in an all-optical trap. A repulsive optical barrier across one side of the torus creates a tunable weak link in the condensate circuit, which can affect the current around the loop. Superflow stops abruptly at a barrier strength such that the local flow velocity at the barrier exceeds a critical velocity. The measured critical velocity is consistent with dissipation due to the creation of vortex-antivortex pairs. This system is the first realization of an elementary closed-loop atom circuit.
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Superflow in a toroidal bose einstein condensate an atom circuit with a tunable weak link
Physical Review Letters, 2011Co-Authors: Anand Ramanathan, Kevin Wright, C J Lobb, William D Phillips, S R Muniz, Martin Zelan, W T Hill, Kristian Helmerson, G K CampbellAbstract:We have created a long-lived ($\ensuremath{\approx}40\text{ }\text{ }\mathrm{s}$) persistent current in a toroidal Bose-Einstein condensate held in an all-optical trap. A repulsive optical barrier across one side of the torus creates a tunable weak link in the condensate circuit, which can affect the current around the loop. Superflow stops abruptly at a barrier strength such that the local flow velocity at the barrier exceeds a critical velocity. The measured critical velocity is consistent with dissipation due to the creation of vortex-antivortex pairs. This system is the first realization of an elementary closed-loop atom circuit.
Stuart Moulder - One of the best experts on this subject based on the ideXlab platform.
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quantized supercurrent decay in an annular bose einstein condensate
Physical Review A, 2012Co-Authors: Stuart Moulder, Scott Beattie, Robert P Smith, Naaman Tammuz, Zoran HadzibabicAbstract:We study the metastability and decay of multiply-charged Superflow in a ring-shaped atomic Bose-Einstein condensate. Supercurrent corresponding to a giant vortex with topological charge up to q=10 is phase-imprinted optically and detected both interferometrically and kinematically. We observe q=3 Superflow persisting for up to a minute and clearly resolve a cascade of quantised steps in its decay. These stochastic decay events, associated with vortex-induced $2 \pi$ phase slips, correspond to collective jumps of atoms between discrete q values. We demonstrate the ability to detect quantised rotational states with > 99 % fidelity, which allows a detailed quantitative study of time-resolved phase-slip dynamics. We find that the supercurrent decays rapidly if the Superflow speed exceeds a critical velocity in good agreement with numerical simulations, and we also observe rare stochastic phase slips for Superflow speeds below the critical velocity.
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quantized supercurrent decay in an annular bose einstein condensate
Physical Review A, 2012Co-Authors: Stuart Moulder, Scott Beattie, Robert P Smith, Naaman Tammuz, Zoran HadzibabicAbstract:We study the metastability and decay of multiply-charged Superflow in a ring-shaped atomic Bose-Einstein condensate. Supercurrent corresponding to a giant vortex with topological charge up to q=10 is phase-imprinted optically and detected both interferometrically and kinematically. We observe q=3 Superflow persisting for up to a minute and clearly resolve a cascade of quantised steps in its decay. These stochastic decay events, associated with vortex-induced $2 \pi$ phase slips, correspond to collective jumps of atoms between discrete q values. We demonstrate the ability to detect quantised rotational states with > 99 % fidelity, which allows a detailed quantitative study of time-resolved phase-slip dynamics. We find that the supercurrent decays rapidly if the Superflow speed exceeds a critical velocity in good agreement with numerical simulations, and we also observe rare stochastic phase slips for Superflow speeds below the critical velocity.
