Universal Error Bound for Constrained Quantum Dynamics
- June 24 at 16:00 - 18:10, 2020
- Dr. Ryusuke Hamazaki (Senior Research Scientist, iTHEMS)
- via Zoom
In quantum mechanics, the existence of large energy gaps allows us to trace out the degrees of freedom of irrelevant energy scale. Consequently, we can treat a system within a constrained subspace obtained by the projection of the total Hilbert space. While this statement has widely been used to approximate quantum dynamics in various contexts, a general and quantitative justification stays lacking.
In this talk, we show a universal and rigorous error bound for such a constrained-dynamics approximation in generic gapped quantum systems [1,2]. This universal bound is a linear function of time that only involves the energy gap and coupling strength, provided that the latter is much smaller than the former. If time allows, I will briefly talk about generalizations of our result to e.g., quantum many-body systems and open quantum systems.
*Please contact Keita Mikami's mail address to get access to the Zoom meeting room.
- Z. Gong, N. Yoshioka, N. Shibata, and RH, Phys. Rev. Lett. 124, 210606 (2020).
- Z. Gong, N. Yoshioka, N. Shibata, and RH, Phys. Rev. A 101, 052122 (2020).