Resonant Spin-Changing Collisions in Spinor Fermi Gases

Bornemann, Nils; Hyllus, Philipp; Santos, Luís

doi:10.1103/physrevlett.100.205302

Cited by 6 publications

(7 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…, spinchanging collisions [37][38][39][40] can transfer the atoms into new states 1 2 ,   m m at low magnetic field. For increasing spin length, the number of involved two-particle states typically increases.…”

Section: Principles Of Fermionic Spin-changing Collisionsmentioning

confidence: 99%

Coherent multi-flavour spin dynamics in a fermionic quantum gas

Krauser

Heinze²,

Fläschner³

et al. 2012

Nature Phys

132

View full text Add to dashboard Cite

Microscopic spin interaction processes are fundamental for global static and dynamical magnetic properties of many-body systems. Quantum gases as pure and well isolated systems offer intriguing possibilities to study basic magnetic processes including non-equilibrium dynamics. Here, we report on the realization of a well-controlled fermionic spinor gas in an optical lattice with tunable effective spin ranging from 1/2 to 9/2. We observe long-lived intrinsic spin oscillations and investigate the transition from two-body to many-body dynamics. The latter results in a spin-interaction driven melting of a band insulator. Via an external magnetic field we control the system's dimensionality and tune the spin oscillations in and out of resonance. Our results open new routes to study quantum magnetism of fermionic particles beyond conventional spin 1/2 systems.Comment: 9 pages, 5 figure

show abstract

Section: Principles Of Fermionic Spin-changing Collisionsmentioning

confidence: 99%

Coherent multi-flavour spin dynamics in a fermionic quantum gas

Krauser

Heinze²,

Fläschner³

et al. 2012

Nature Phys

132

View full text Add to dashboard Cite

show abstract

“…Once the gas is cooled down, a 3D lattice is grown and under proper conditions a Mott insulator with one particle per site develops at the trap center [5,6]. The next step consists in slowly lowering the magnetic field to allow for quasi-resonant spin-changing collisions [35] throughout the sample leading to a redistributed population (between F = 9/2, M F = −3/2, −5/2, −7/2, and −9/2 [36]) and a significant drop of T in the lattice. Temperature drop after this stage for 1D case, (assuming adiabaticity) is depicted on Fig.…”

Section: Experimental Feasibilitymentioning

confidence: 99%

Adiabatic spin cooling using high-spin Fermi gases

et al. 2011

View full text Add to dashboard Cite

Spatial entropy redistribution plays a key role in the adiabatic cooling of ultra-cold lattice gases. We show that high-spin fermions with a spatially variable quadratic Zeeman coupling may allow for the creation of an inner spin-1/2 core surrounded by high-spin wings. The latter are always more entropic than the core at high temperatures, and remarkably at all temperatures in the presence of frustration. Combining thermodynamic Bethe Ansatz with local density approximation, we study the spatial entropy distribution for the particular case of one-dimensional spin-3/2 lattice fermions in the Mott-phase. Interestingly, this spatially-dependent entropy opens a possible path for an adiabatic cooling technique which contrary to previous proposals, would specifically target the spin degree of freedom. We discuss a possible realization of this adiabatic cooling, which may allow for a high-efficient entropy decrease in the spin-1/2 core and help accessing antiferromagnetic order in experiments on ultracold spinor fermions.

show abstract

“…The two others are entangled states of orbital and spin degrees of freedom. Similar states produced by spinchanging collisions have also been discussed in the context of Fermi spinor gases [33].…”

mentioning

confidence: 96%

Resonant demagnetization of a dipolar Bose-Einstein condensate in a three-dimensional optical lattice

et al. 2013

View full text Add to dashboard Cite

We study dipolar relaxation of a chromium Bose-Einstein condensate loaded into a three-dimensional (3D) optical lattice. We observe dipolar relaxation resonances when the magnetic energy released during the inelastic collision matches an excitation towards higher-energy bands. Spectroscopy of these resonances for two orientations of the magnetic field provides a 3D band spectroscopy of the lattice. The narrowest resonance is registered for the lowest excitation energy. Its line shape is sensitive to the on-site interaction energy. We use such sensitivity to probe number squeezing in a Mott insulator. Quantum dipolar gases have attracted much attention in recent years [1][2][3]. Following the seminal studies of Cr BoseEinstein condensates (BECs) [4][5][6][7] and the recent production of Er [8] and Dy [9,10] quantum gases, it is natural to study dipolar gases confined in optical lattices. Dipolar gases in lattices provide an ideal playground for studying quantum phase transitions in a system with long-range interactions. The unique properties of dipole-dipole interactions (DDIs) present direct similarities with the Heisenberg model of quantum magnetism [11][12][13][14] and lead to novel quantum phases displaying possible long-range ordering in lattices [15][16][17]. The nonlinear coupling between spin and orbital degrees of freedom provided by dipolar interactions [18][19][20][21][22][23] is particularly interesting. Although at large magnetic field, this coupling leads to fast dipolar relaxation losses for atoms in excited spin states [24], we have recently demonstrated that working at low magnetic field enables the study of multicomponent quantum gases with free magnetization [25,26]. Here we extend this research to include dipolar particles trapped in optical lattices and directly observe discrete, atom-number-dependent coupling between spin and orbital degrees of freedom.We study the magnetization dynamics of 52 Cr atoms loaded in a deep three-dimensional (3D) optical lattice. Under our experimental conditions, we produce a Mott insulator state with a core of two particles per site [27,28]. Compared to our previous results in two-dimensional (2D) optical lattices [23], the 3D confinement allows us to reach a new regime, where on-site dipolar relaxation is inhibited unless the released magnetic energy matches a lattice band excitation: dipolar relaxation is a resonant process. The interplay between the anisotropies of dipolar interaction and of lattice sites leads to a resonance spectrum which depends on the magnetic-field orientation. Measuring demagnetization as a function of the magnetic field for two orientations allows for spectroscopy of the 3D lattice band structure. We operate in an asymmetric 3D lattice such that the narrowest resonance is found to be sensitive to the on-site atom-number distribution and reveals the number-squeezed distribution of the Mott state. Changing our experimental conditions, we prepare sites containing three atoms. Spin-orbit coupling DDI then produces three-body states that a...

show abstract

Resonant Spin-Changing Collisions in Spinor Fermi Gases

Cited by 6 publications

References 26 publications

Coherent multi-flavour spin dynamics in a fermionic quantum gas

Coherent multi-flavour spin dynamics in a fermionic quantum gas

Adiabatic spin cooling using high-spin Fermi gases

Resonant demagnetization of a dipolar Bose-Einstein condensate in a three-dimensional optical lattice

Contact Info

Product

Resources

About