Quantum engineering with ultracold polar molecules using trap-induced resonances

Abstract

Polar molecules represent a promising platform for quantum simulation and computation protocols. Highly controllable arrays of optical tweezers are now accessible in experiments, allowing for unprecedented control of individual molecules. Motional dephasing is typically seen as an obstacle in quantum computing scenarios. Here, we instead consider using the trap structure as a resource for implementing efficient quantum gates. By numerically solving the two-body problem of dipoles trapped in separate tweezers, we identify trap-induced resonances that can serve as the mechanism for achieving state-dependent dynamics and can be further utilized for quantum sensing.

Figures (6)

• Figure 1: Left: the setup consisting of two molecules trapped in individual optical tweezers, with an electric field pointing along the intermolecular axis. Right: the basic mechanism behind the occurrence of a trap-induced resonance.
• Figure 2: Interaction properties for the considered qubit pair states, expressed in dimensionless form.
• Figure 3: Pictorial representation of the Numerov algorithm. Starting from the solution at the boundary, we iteratively propagate the wavefunction from both sides to the intermediate matching point. If the initial energy used in propagation is close enough to the eigenvalue of the system, then continuity condition at the matching point can be met and this is the solution of the Schrödinger equation.
• Figure 4: Energy levels as a function of tweezer separation for NaCs molecules with $\omega = 100$ kHz, $\eta = 2$, $C_6 = 8.21277 \cdot 10^6$ atomic units and $C_3 = 0$. The spectrum is produced for the angular momentum projection $m = 0$. The red dashed line denotes expected quadratic scaling of the molecular state energy, while the symbols mark the positions of unperturbed harmonic oscillator states. We denote them by $\ket{n_{xy}, n_z}$, where $n_{xy} = n_x = n_y$ which is a relation fullfilled for $m=0$.
• Figure 5: Energy spectrum for the same system as in Fig. \ref{['fig:trap_res_nodip']}, but including moderate dipolar interaction ($R_3/R_6 = 1$).