Triple-well challenge

This exercise is the final part of the quantum control workshop that we hold for all new students and interns. At the end of this exercise, students are asked to write a report on their findings.

The exercise asks students to solve the problem of transferring a particle (or BEC) wavefunction from the first to the third well of a three-well system by controlling the heights of the barriers between the wells

Students can explore this control problem by manipulating points on a graph directly, adjusting parameters in an analytic formula, or using the GRAPE algorithm. In each case, students are manipulating the potential modulation (shaking) function.

Note that in the case of BEC control in an anharmonic potential, students are solving the same control problem as players of the Shake Up level in our citizen science game Quantum Moves 2. Therefore, we encourage students to explore the game as well!

Because there are so many different avenues a student can explore, we leave it up to the student to choose what to study. For example, students could write reports on:

  • Analyzing strategies of how they personally adjust parameters to optimize curves
  • Comparing quantum speed limits for different values of the nonlinearity in the BEC problem

This exercise can be modified to incorporate other challenges or personalize it for different scenarios and classrooms, please just contact us. LaTeX files for the exercise PDF and report templates are available as well upon request. Contact Carrie at for more information.

We have also developed a nice introduction to numerical quantum calculations and quantum optimal control that you can find here.

Key words and phrases: quantum control, multi-well systems, particle and BEC excitation, nonlinearity

The PDF file for this exercise can be found here.

A zip folder containing all the flow files for this exercise can be found here.