Standard optical potentials use off-resonant laser standing wave induced AC-Stark shift. In a recent development [Phys. Rev. Lett. {\bf 117}, 233001 (2016)] a three-level scheme in Λ configuration coupled coherently by resonant laser fields was introduced leading to an effective lattice with subwavelength potential peaks. Here as an extension of that work to a four level atomic setup in the tripod configuration is used to create spin 1/2-like two-dimensional dark-space with 1D motion and the presence of external gauge fields. Most interestingly for a possible application, the lifetime for a dark subspace motion is up to two orders of magnitude larger than for a similar Λ system. The model is quite flexible leading to lattices with significant nearest, next-nearest, or next-next-nearest hopping rates, J1,J2,J3 opening up new intriguing possibilities to study, e.g. frustrated systems. The characteristic Wannier functions lead also to new type of inter-site interactions not realizable in typical optical lattices.
[Parent Directory]Bands | DIR | Band structures for the Tripod system, in analogy to Fig. 3, panels a,b,c,d subsequently. |
GaugePotentials | DIR | Gauge potentials in Figs. 2 and 9. |
Hoppings | DIR | Hoppings $J^\alpha$ as in Fig.6. |
WannierFunctions | DIR | Wannier functions in g1,g2,g3,e basis in position representation, $a=0.435$. |
Bands.zip | 160kB | |
GaugePotentials.zip | 391kB | |
Hoppings.zip | 23kB | |
WannierFunctions.zip | 631kB |