Berkeley Lab
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Qutrit Logic

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  • Project Team :Alexis Morvan
  • Collaborators :
  • Date :25 August, 2017
  • Status :In Process
  • Relevant Publications:https://dx.doi.org/10.1103/PhysRevA.75.022313
    https://arxiv.org/abs/2003.03307
    Article in preparation

Project Description

Higher energy levels of a quantum processor are usually considered an annoyance. It leaves room for leakage and coherent errors that can be hard to diagnose and mitigate. But they can also be seen as a quantum resource. One can use the larger Hilbert space to implement algorithms more compactly. Another advantage of introducing these levels is the possibility to reduce the number of entanglement gates to perform complex gates like the Toffoli gate

In our group, we are trying to take advantage of the multi-level structure of our transmon 8-qubits chip to construct a qutrit quantum processor rather than a qubit-based one. There are several aspects to this work: First, we have implemented qutrit singles gates and entanglement gates, overcoming the difficulties coming from crosstalk and controlling a larger control space. Using this architecture, we have showcased a multi-qutrit algorithm using 5 qutrits to simulate the Scrambling of information of a Black Hole [2]. Finally, the last aspect of this project is to develop a useful metric to assess the performance of qutrit-based processors and how to compare it to a qubit-based processor. For this last question, we have generalized several randomized benchmarking protocols to qutrits and performed characterization with these techniques.

What we did

  • We have successfully implemented a 5-qutrit algorithm to simulate the Scrambling of information by a Black Hole
  • We have developed qutrit singles gates as well as qutrit entanglement gates
  • Finally, we have generalized and applied Randomized Benchmarking to our qutrit processor to compare its performance to a qubit-based one
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Current Status & Next Steps

Now that we have showcased an algorithm based on a qutrit architecture and developed tools to benchmark the performance of qutrit-based quantum processor, we keep working on improving our qutrit gates, both single qutrit and entanglement gates. We strongly believe that developing more qutrit tools will help us to diagnose qubits processor as well and profit for both architectures. We also plan to use our qutrit gates to enhance the performance of various algorithms.