![]() Figure 1c shows the Raman Rabi oscillation between the \(\left|\uparrow \right\rangle\) and \(\left|\downarrow \right\rangle\) states. ![]() We perform the coherent spin manipulation using the Raman transition between the \(\left|\uparrow \right\rangle\) and \(\left|\downarrow \right\rangle\) states 20 (see “Methods”). By utilizing the mixed dimensional experimental platform consisting of the two-orbital system with an itinerant one-dimensional (1D) repulsively interacting Fermi gas in the ground state \(\left|g\right\rangle\) = \(=-5/2\right\rangle\) state is responsible for the localized impurity, where m F denotes the projection of the hyperfine spin F = I onto the quantization axis defined by a magnetic field. In this work, we successfully demonstrate the spin-space quantum transport induced by an atomic QPC using ultracold ytterbium atoms of 173Yb with the nuclear spin I = 5/2. In addition, since the QPC in this scheme is also an atom with internal degrees of freedom, this system provides an intriguing possibility for the study of the nonequilibrium Anderson’s orthogonality catastrophe by measuring the spin coherence of the localized impurity 13. This spin-space scheme shares with the above-mentioned real-space scheme the coherent character of terminals consisting of ultracold atoms isolated from an environment and the controllability of the interatomic interactions. Consequently, multiterminal quantum transport via a QPC can be realized by working with the multiple spin components of atoms 14. The spin degrees of freedom of the Fermi gas and the localized impurity correspond to the terminals and the QPC, respectively. The itinerant atom obtains a spin-dependent phase shift via an impurity scattering, resulting in the quantum transport in the synthetic dimension of spin space instead of the real space, thus evading the need for preparation of elaborated potentials for atoms. Different from the spin transport experiments with spatially separated spin distribution 15, 16, 17, 18, this proposal considers a spatially overlapped cloud of itinerant spinful Fermi gases interacting with a localized impurity. More recently, a scheme of a quantum transport experiment that exploits the spin degrees of freedom of ultracold atoms has been proposed 11, 12, 13, 14. In addition, owing to the ability of manipulating the reservoirs or terminals that possess coherent character for the ultracold atoms isolated from an environment, the effect of fermion superfluidity of the reservoirs was revealed 10. As a specific example, by creating a mesoscopic quantum point contact (QPC) structure in real space with sophisticatedly designed optical potentials for ultracold atoms, the quantization of conductance between two terminals, expected from the Landauer–Büttiker formula 7, 8, was successfully demonstrated 9. In recent years, the quantum simulations using ultracold atomic gases, which successfully reproduced paradigmatic models of condensed matter physics 3, have extended the domain into quantum transport experiments 4, 5, often called atomtronics 6. A transport measurement between terminals has played an important role, especially for solid-state systems, in the fundamental studies of the quantum systems such as the quantized conductance and the quantum many-body effect like superconductivity and the Kondo effect as well as in the applications for electronic devices 1, 2.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |