تقرير
Quantum Coding Transitions in the Presence of Boundary Dissipation
| العنوان: | Quantum Coding Transitions in the Presence of Boundary Dissipation |
|---|---|
| المؤلفون: | Lovas, Izabella, Agrawal, Utkarsh, Vijay, Sagar |
| سنة النشر: | 2023 |
| المجموعة: | Condensed Matter Quantum Physics |
| مصطلحات موضوعية: | Quantum Physics, Condensed Matter - Disordered Systems and Neural Networks, Condensed Matter - Statistical Mechanics |
| الوصف: | We investigate phase transitions in the encoding of quantum information in a quantum many-body system due to the competing effects of unitary scrambling and boundary dissipation. Specifically, we study the fate of quantum information in a one-dimensional qudit chain, subject to local unitary quantum circuit evolution in the presence of depolarizating noise at the boundary. If the qudit chain initially contains a finite amount of locally-accessible quantum information, unitary evolution in the presence of boundary dissipation allows this information to remain partially protected when the dissipation is sufficiently weak, and up to time-scales growing linearly in system size $L$. In contrast, for strong enough dissipation, this information is completely lost to the dissipative environment. We analytically investigate this ``quantum coding transition" by considering dynamics involving Haar-random, local unitary gates, and confirm our predictions in numerical simulations of Clifford quantum circuits. We demonstrate that scrambling the quantum information in the qudit chain with a unitary circuit of depth $ \mathcal{O}(\log L)$ before the onset of dissipation can perfectly protect the information until late times. The nature of the coding transition changes when the dynamics extend for times much longer than $L$. We further show that at weak dissipation, it is possible to code at a finite rate, i.e. a fraction of the many-body Hilbert space of the qudit chain can be used to encode quantum information. Comment: 21 pages, 14 figures |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2304.02664 |
| رقم الأكسشن: | edsarx.2304.02664 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |