Feshbach resonances are the essential tool to control the interaction between atoms in ultracold quantum gases. They have found numerous experimental applications, opening up the way to important breakthroughs. This review broadly covers the phenomenon of Feshbach resonances in ultracold gases and their main applications. This includes the theoretical background and models for the description of Feshbach resonances, the experimental methods to find and characterize the resonances, a discussion of the main properties of resonances in various atomic species and mixed atomic species systems, and an overview of key experiments with atomic Bose-Einstein condensates, degenerate Fermi gases, and ultracold molecules.Feshbach resonances are the essential tool to control the interaction between atoms in ultracold quantum gases. They have found numerous experimental applications, opening up the way to important breakthroughs. This review broadly covers the phenomenon of Feshbach resonances in ultracold gases and their main applications. This includes the theoretical background and models for the description of Feshbach resonances, the experimental methods to find and characterize the resonances, a discussion of the main properties of resonances in various atomic species and mixed atomic species systems, and an overview of key experiments with atomic Bose-Einstein condensates, degenerate Fermi gases, and ultracold molecules.

arXiv:0812.1496Reviews of Modern PhysicsApr 29, 20103,854 citations

Bose–Einstein condensation in ultracold atomic gases

S. Stringari

Physics Letters AOct 3, 20057 citations

Feshbach resonances in atomic Bose–Einstein condensates

E.A.H. Timmermans

Physics ReportsJul 1, 1999609 citations

Bose polarons and rotating gases in an ultracold Bose-Fermi gas mixture of 40K and 87Rb atoms

Ming-Guang Hu

An ultracold Bose-Fermi gas mixture of 40K and 87Rb atoms has tunable interspecies interactions and therefore provides a fantastic platform for exploring not only few-body physics such as Feshbach molecule formation and Efimov trimers, but also many-body physics including Bose polarons, quantum Hall physics and so on. In this thesis, I present experimental evidence of Bose polarons in cold atoms obtained using radio-frequency spectroscopy to measure the excitation spectrum of fermionic 40K impurities resonantly interacting with a BEC of 87Rb atoms. These Bose polarons originate from the dressing of an impurity coupled to its environment, which is an important paradigm in quantum many-body physics. I also present initial work that launches an exciting new direction for our experiment, which is exploring rotating quantum gases. Goals for this work include studying both rotating Bose and Fermi superfluids with tunable interactions as well as working toward rapidly rotating quantum gases in the quantum Hall regime. For these goals, a new all-optical trap for rotating gases was designed, implemented, and tested using a 87Rb Bose-Einstein condensate.An ultracold Bose-Fermi gas mixture of 40K and 87Rb atoms has tunable interspecies interactions and therefore provides a fantastic platform for exploring not only few-body physics such as Feshbach molecule formation and Efimov trimers, but also many-body physics including Bose polarons, quantum Hall physics and so on. In this thesis, I present experimental evidence of Bose polarons in cold atoms obtained using radio-frequency spectroscopy to measure the excitation spectrum of fermionic 40K impurities resonantly interacting with a BEC of 87Rb atoms. These Bose polarons originate from the dressing of an impurity coupled to its environment, which is an important paradigm in quantum many-body physics. I also present initial work that launches an exciting new direction for our experiment, which is exploring rotating quantum gases. Goals for this work include studying both rotating Bose and Fermi superfluids with tunable interactions as well as working toward rapidly rotating quantum gases in the quantum Hall regime. For these goals, a new all-optical trap for rotating gases was designed, implemented, and tested using a 87Rb Bose-Einstein condensate.

Jan 1, 20160 citations

Dual-species Bose-Einstein condensates of $^{23}$ Na and $^{41}$ K with tunable interactionsDual-species Bose-Einstein condensates of $^{23}$Na and $^{41}$K with tunable interactions

Jaeryeong Chang, Sung‐Jun Lee, Yoonsoo Kim +2 more

We report the creation of dual-species Bose-Einstein condensates (BECs) of $^{23}$ Na and $^{41}$ K. Favorable background scattering lengths enable efficient sympathetic cooling of $^{41}$ K via forced evaporative cooling of $^{23}$ Na in a plugged magnetic trap and an optical dipole trap. The $1/e$ lifetime of the thermal mixture in the stretched hyperfine state exceeds 5 s in the presence of background scattering. At the end of evaporation, we create dual BECs in the immiscible phase, with about $3\times10^5$ $^{23}$ Na atoms surrounding $5\times10^4$ $^{41}$ K atoms. To further enable the tuning of the interspecies interaction strength, we locate multiple Feshbach resonances at magnetic fields up to 100 G. The broadest $s$ -wave resonance located at 73.4(3) G features a favorable width of 1.8(2) G. This work sets the stage for the creation of ultracold gases of strongly dipolar bosonic $^{23}$ Na $^{41}$ K molecules as well as the exploration of many-body physics in bosonic $^{23}$ Na- $^{41}$ K mixtures.We report the creation of dual-species Bose-Einstein condensates (BECs) of $^{23}$Na and $^{41}$K. Favorable background scattering lengths enable efficient sympathetic cooling of $^{41}$K via forced evaporative cooling of $^{23}$Na in a plugged magnetic trap and an optical dipole trap. The $1/e$ lifetime of the thermal mixture in the stretched hyperfine state exceeds 5 s in the presence of background scattering. At the end of evaporation, we create dual BECs in the immiscible phase, with about $3\times10^5$ $^{23}$Na atoms surrounding $5\times10^4$ $^{41}$K atoms. To further enable the tuning of the interspecies interaction strength, we locate multiple Feshbach resonances at magnetic fields up to 100 G. The broadest $s$-wave resonance located at 73.4(3) G features a favorable width of 1.8(2) G. This work sets the stage for the creation of ultracold gases of strongly dipolar bosonic $^{23}$Na$^{41}$K molecules as well as the exploration of many-body physics in bosonic $^{23}$Na-$^{41}$K mixtures.

arXiv:2312.08186Dec 13, 20230 citations

Feshbach resonances in Bose-Einstein condensates

JM Johnny Vogels

Jan 1, 19992 citations

Dual-species Bose-Einstein condensates of

^{23}

Na and

^{41}

K with tunable interactions

We report the creation of dual-species Bose-Einstein condensates (BECs) of

^{23}

Na and

^{41}

K. Favorable background scattering lengths enable efficient sympathetic cooling of

^{41}

K via forced evaporative cooling of

^{23}

Na in a plugged magnetic trap and an optical dipole trap. The

1/e

lifetime of the thermal mixture in the stretched hyperfine state exceeds 5 s in the presence of background scattering. At the end of evaporation, we create dual BECs in the immiscible phase, with about

3\times10^5

^{23}

Na atoms surrounding

5\times10^4

^{41}

K atoms. To further enable the tuning of the interspecies interaction strength, we locate multiple Feshbach resonances at magnetic fields up to 100 G. The broadest

s

-wave resonance located at 73.4(3) G features a favorable width of 1.8(2) G. This work sets the stage for the creation of ultracold gases of strongly dipolar bosonic

^{23}

^{41}

K molecules as well as the exploration of many-body physics in bosonic

^{23}

Na-

^{41}

K mixtures.