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Yoshiro Takahashi - One of the best experts on this subject based on the ideXlab platform.
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dissipative bose hubbard system with intrinsic two body loss
Physical Review A, 2019Co-Authors: Takafumi Tomita, Shuta Nakajima, Yosuke Takasu, Yoshiro TakahashiAbstract:We report an experimental study of dynamics of the metastable ${}^{3}{P}_{2}$ state of bosonic ytterbium atoms in an optical lattice. The dissipative Bose-Hubbard system with on-site two-body atom loss is realized via its intrinsic strong Inelastic Collision of the metastable ${}^{3}{P}_{2}$ atoms. We investigate the atom loss behavior with the unit-filling Mott insulator as the initial state and find that the atom loss is suppressed by the strong correlation between atoms, which is attributed to both the on-site interaction and the Inelastic loss. Also, as we decrease the potential depth of the lattice, we observe the growth of the phase coherence and find its suppression owing to the dissipation.
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observation of the mott insulator to superfluid crossover of a driven dissipative bose hubbard system
Science Advances, 2017Co-Authors: Takafumi Tomita, Shuta Nakajima, Yosuke Takasu, Ippei Danshita, Yoshiro TakahashiAbstract:Dissipation is ubiquitous in nature and plays a crucial role in quantum systems such as causing decoherence of quantum states. Recently, much attention has been paid to an intriguing possibility of dissipation as an efficient tool for the preparation and manipulation of quantum states. We report the realization of successful demonstration of a novel role of dissipation in a quantum phase transition using cold atoms. We realize an engineered dissipative Bose-Hubbard system by introducing a controllable strength of two-body Inelastic Collision via photoassociation for ultracold bosons in a three-dimensional optical lattice. In the dynamics subjected to a slow ramp-down of the optical lattice, we find that strong on-site dissipation favors the Mott insulating state: The melting of the Mott insulator is delayed, and the growth of the phase coherence is suppressed. The controllability of the dissipation is highlighted by quenching the dissipation, providing a novel method for investigating a quantum many-body state and its nonequilibrium dynamics.
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spin dependent Inelastic Collisions between metastable state two electron atoms and ground state alkali atoms
New Journal of Physics, 2017Co-Authors: Florian Schafer, Hideki Konishi, Adrien Bouscal, Tomoya Yagami, Yoshiro TakahashiAbstract:Experimentally the spin dependence of Inelastic Collisions between ytterbium (Yb) in the metastable state and lithium (Li) in the ground state manifold is investigated at low magnetic fields. Using selective excitation all magnetic sublevels m J of Yb() are accessed and four of the six lowest lying magnetic sublevels of are prepared by optical pumping. On the one hand, m J -independence of Collisions involving Li() atoms is found. A systematic m J -dependence in Collisions with Li() atoms, in particular suppressed losses for stretched Collisional states, is observed on the other hand. Further, m J -changing processes are found to be of minor relevance. The span of observed Inelastic Collision rates is between and , and a possible origin of the observed behavior is discussed.
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Inelastic Collisions in optically trapped ultracold metastable ytterbium
Physical Review Letters, 2008Co-Authors: A Yamaguchi, John M Doyle, Satoshi Uetake, D Hashimoto, Yoshiro TakahashiAbstract:We report measurement of Inelastic loss in dense and cold metastable ytterbium (Yb[3P2]). Use of an optical far-off-resonance trap enables us to trap atoms in all magnetic sublevels, removing m-changing Collisional trap loss from the system. Trapped samples of Yb[3P2] are produced at a density of 2 x 10(13) cm(-3) and temperature of 2 microK. We observe rapid two-body trap loss of Yb[3P2] and measure the Inelastic Collision rate constant 1.0(3) x 10(-11) cm3 s(-1). The existence of the fine-structure changing Collisions between atoms in the 3P2 state is strongly suggested.
John M Doyle - One of the best experts on this subject based on the ideXlab platform.
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zeeman relaxation induced by spin orbit coupling in cold antimony helium Collisions
Physical Review A, 2013Co-Authors: Colin B Connolly, Eunmi Chae, Timur V Tscherbul, Alexei A Buchachenko, Wolfgang Ketterle, John M DoyleAbstract:We investigate Zeeman relaxation in cold Sb(${}^{4}{S}_{3/2}^{\ensuremath{\circ}}$)--He Collisions in a magnetic field. Ensembles of $g$${10}^{13}$ laser-ablated Sb atoms are cooled in cryogenic ${}^{4}$He buffer gas to 800 mK and Inelastic Collisions are observed to equilibrate the ${m}_{J}$-state distribution to the translational temperature. The ratio $\ensuremath{\gamma}$ of momentum transfer to Inelastic Collision rates is measured to be $\ensuremath{\leqslant}9.1\ifmmode\times\else\texttimes\fi{}{10}^{2}$. We also perform quantum scattering calculations of Sb--${}^{4}$He Collisions, based on ab initio interaction potentials, that demonstrate significant anisotropy of the ground state induced by the spin-orbit interaction. Agreement is obtained between theory and experiment with a $\ensuremath{\approx}$10$%$ increase in the ab initio potential depth. This work suggests that buffer-gas-cooled pnictogen atoms lighter than Sb can be loaded into a magnetic trap.
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zeeman relaxation induced by spin orbit coupling in cold antimony helium Collisions
APS, 2013Co-Authors: Colin B Connolly, Eunmi Chae, Timur V Tscherbul, Alexei A Buchachenko, Wolfgang Ketterle, John M DoyleAbstract:We investigate Zeeman relaxation in cold Sb( 4 S ◦/2)–He Collisions in a magnetic field. Ensembles of >10 13 laser-ablated Sb atoms are cooled in cryogenic 4 He buffer gas to 800 mK and Inelastic Collisions are observed to equilibrate the mJ -state distribution to the translational temperature. The ratio γ of momentum transfer to Inelastic Collision rates is measured to be 9.1 × 10 2 . We also perform quantum scattering calculations of Sb– 4 He Collisions, based on ab initio interaction potentials, that demonstrate significant anisotropy of the ground state induced by the spin-orbit interaction. Agreement is obtained between theory and experiment with a ≈10% increase in the ab initio potential depth. This work suggests that buffer-gas-cooled pnictogen atoms lighter than
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Inelastic Collisions in optically trapped ultracold metastable ytterbium
Physical Review Letters, 2008Co-Authors: A Yamaguchi, John M Doyle, Satoshi Uetake, D Hashimoto, Yoshiro TakahashiAbstract:We report measurement of Inelastic loss in dense and cold metastable ytterbium (Yb[3P2]). Use of an optical far-off-resonance trap enables us to trap atoms in all magnetic sublevels, removing m-changing Collisional trap loss from the system. Trapped samples of Yb[3P2] are produced at a density of 2 x 10(13) cm(-3) and temperature of 2 microK. We observe rapid two-body trap loss of Yb[3P2] and measure the Inelastic Collision rate constant 1.0(3) x 10(-11) cm3 s(-1). The existence of the fine-structure changing Collisions between atoms in the 3P2 state is strongly suggested.
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magnetic trapping of silver and copper and anomalous spin relaxation in the ag he system
Physical Review Letters, 2008Co-Authors: Nathan Brahms, Bonna Newman, Cort Johnson, T J Greytak, Daniel Kleppner, John M DoyleAbstract:We have trapped large numbers of copper (Cu) and silver (Ag) atoms using buffer-gas cooling. Up to 3 x 10{12} Cu atoms and 4 x 10{13} Ag atoms are trapped. Lifetimes are as long as 5 s, limited by Collisions with the buffer gas. Ratios of elastic to Inelastic Collision rates with He are >or=10{6}, suggesting Cu and Ag are favorable for use in ultracold applications. The temperature dependence of the Ag-3He Collision rate varies as T;{5.8+/-0.4}. We find that this temperature dependence is inconsistent with the behavior predicted for relaxation arising from the spin-rotation interaction, and conclude that the Ag-3He system displays anomalous Collisional behavior in the multiple-partial wave regime. Gold (Au) was ablated into 3He buffer gas, however, atomic Au lifetimes were observed to be too short to permit trapping.
Eric R Hudson - One of the best experts on this subject based on the ideXlab platform.
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role of electronic excitations in ground state forbidden Inelastic Collisions between ultracold atoms and ions
Physical Review Letters, 2012Co-Authors: Scott T Sullivan, Svetlana Kotochigova, Wade G Rellergert, Eric R HudsonAbstract:The role of electronic excitation in Inelastic Collisions between ultracold Ca atoms and ${\mathrm{Ba}}^{+}$ ions, confined in a hybrid trap, is studied for the first time. Unlike previous investigations, this system is energetically precluded from undergoing Inelastic Collisions in its ground state, allowing a relatively simple experimental determination and interpretation of the influence of electronic excitation. It is found that while the electronic state of the ion can critically influence the Inelastic Collision rate, the polarizability mismatch of the neutral atom electronic states suppresses short-range Collisions, and thus Inelastic processes, involving electronically excited neutral atoms. As a result of these features, it is experimentally demonstrated that it is possible to mitigate Inelastic Collision loss mechanisms in these systems, marking an important step toward long-lived hybrid atom-ion devices.
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Inelastic Collisions of ultracold heteronuclear molecules in an optical trap
Physical Review Letters, 2008Co-Authors: Eric R Hudson, Nathan Gilfoy, Svetlana Kotochigova, Jeremy M Sage, David DemilleAbstract:Ultracold RbCs molecules in high-lying vibrational levels of the a 3 Σ + ground electronic state are confined in an optical trap. Inelastic Collision rates of these molecules with both Rb and Cs atoms are determined for individual vibrational levels, across an order of magnitude of binding energies. The long-range dispersion coefficients for the Collision process are calculated and used in a model that accurately reproduce the observed scattering rates.
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Inelastic Collisions of ultracold heteronuclear molecules in an optical trap
Physical Review Letters, 2008Co-Authors: Eric R Hudson, Nathan Gilfoy, Svetlana Kotochigova, Jeremy M Sage, David DemilleAbstract:Ultracold RbCs molecules in high-lying vibrational levels of the ${a}^{3}{\ensuremath{\Sigma}}^{+}$ ground electronic state are confined in an optical trap. Inelastic Collision rates of these molecules with both Rb and Cs atoms are determined for individual vibrational levels, across an order of magnitude of binding energies. The long-range dispersion coefficients for the Collision process are calculated and used in a model that accurately reproduce the observed scattering rates.
Jinfeng Liao - One of the best experts on this subject based on the ideXlab platform.
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glasma evolution and bose einstein condensation with elastic and Inelastic Collisions
Physical Review D, 2015Co-Authors: Jinfeng Liao, Xuguang HuangAbstract:In this paper we investigate the role of Inelastic Collisions in the kinetic evolution of a highly overpopulated gluon system starting from a glasma-type initial condition. Using the Gunion-Bertsch formula we derive the Inelastic Collision kernel under the collinear and small-angle approximations. With both numerics and analytic analysis, we show that the Inelastic process has two effects: globally changing (mostly reducing) the total particle number, while locally in the small-momentum regime always filling up the infrared modes extremely quickly. This latter effect is found to significantly speed up the emergence of a local thermal distribution in the infrared regime with vanishing local ``chemical potential'' and thus catalyze the onset of dynamical Bose-Einstein condensation to occur faster (as compared with the purely elastic case) in the overpopulated glasma.
Matthew T Hummon - One of the best experts on this subject based on the ideXlab platform.
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electric field induced Inelastic Collisions between magnetically trapped hydroxyl radicals
Bulletin of the American Physical Society, 2013Co-Authors: Benjamin Stuhl, Mark Yeo, Matthew T HummonAbstract:Inelastic Collisions are observed between magnetically trapped neutral hydroxyl (OH•) radicals at a temperature of 45 mK in the presence of an electric field. The Collision rate is measured over a range of electric fields from 0.2 to 10 kV/cm. However, the two-body Collision rates must be deconvolved from a novel electric-field induced non-adiabatic single particle loss, which arises from Landau–Zener crossings between energy surfaces at the plane where the electric field vector is transverse to the trapping magnetic field. The observed Inelastic Collision rate follows an approximate quadratic power law in the effective dipole moment.