FIG. 2. On-site interaction energy U, tunneling energy t, and their ratio U/t as a function of lattice strength and harmonic frequency near the zero-crossing of U. The calculations are for NaCs with Omega = 3.5 MHz, Delta/Omega = 1, and lambda = 1064 nm.

==============================================================================
       V0/E_r      omega (kHz)   U/hbar (kHz)   10t/hbar (kHz)          U/t
==============================================================================
      12.378        7.958          -0.1060           0.1277             -8.3
      12.555        8.015          -0.0459           0.1229             -3.7
      12.732        8.071           0.0143           0.1183              1.2
      12.909        8.127           0.0747           0.1139              6.6
      13.086        8.183           0.1351           0.1097             12.3
      13.263        8.238           0.1955           0.1057             18.5
      13.439        8.292           0.2561           0.1018             25.2
      13.616        8.347           0.3168           0.0981             32.3
      13.793        8.401           0.3775           0.0945             39.9
      13.970        8.455           0.4383           0.0911             48.1
      14.147        8.508           0.4991           0.0878             56.8
