Quantum simulator for the Schwinger effect with atoms in bichromatic optical lattices

Ultracold atoms in specifically designed optical lattices can be used to mimic the many-particle Hamiltonian (whose effective parameters can be tuned in a wide range) describing electrons and positrons in an external electric field. This analogy facilitates the experimental simulation of (so far unobserved) fundamental quantum phenomena such as the Schwinger effect, i.e., spontaneous electron-positron pair creation out of the vacuum by a strong electric field. Such an experiment would also test nonperturbative aspects of these lattice systems.

Figure 1

Sketch of the dispersion relation (in units of $J$ and $1/a$) for $\Delta W=0$ (dashed blue curve) and small $\Delta W>0$ (solid and dotted red curves).

Figure 2

Sketch (not to scale) of the temporal stages of the simulation (from top to bottom). Plotted are the optical lattice potential $W\left(x\right)$ (solid red curves) and the effective electric potential $\Phi \left(x\right)$ (dashed blue curves). The blue solid (empty) dots represent particles (holes).