Description
The diagnosis of quantum circuits is difficult, but at the same time, it is crucial. We construct the positive operator in Liouville space and find some constraints in Liouville space that are applicable to an isolated quantum system. We use positivity in Liouville space to show that these inequalities satisfy an exponential decay law as the number of cycles increases. Consequently, these inequalities are exponentially close to equalities. It isdemonstrated that the deviation from exponential scaling is an indication of the non-ideality of devices, even when no inequality is violated. Using the positivity approach, we explain the previously observed monotonic decrease feature of these constraints and provide an explicit expression for the coefficients of inequality. We demonstrated our findings on the IBM quantum computer and the trapped-ion quantum computer. Violation of scaling actually means there is purity loss in system (physical meaning of violation). Then I will describe how we can measure the purity loss without doing the exact quantum process tomography. I will show some results of the quantum error mitigation technique for non-Markovian noise. Then, at the end, I will show our recent work on synethetic negative temperature.| Period | 31 Dec 2025 |
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| Held at | Virginia Tech, United States, Virginia |
| Degree of Recognition | International |
Keywords
- quantum computing