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| Title: | 探討熱屏蔽塗層對量子位元溫度與讀取保真度的影響
Evaluating the Effect of Shielding on Qubit Temperature and Readout Fidelity |
| Authors: | 呂函諭
Lu, Han-Yu |
| Contributors: | 柯忠廷
Ke, Chung-Ting
呂函諭
Lu, Han-Yu |
| Keywords: | 超導量子位元
讀取保真度
熱屏蔽塗層
紅外光吸收塗層
有效量子位元溫度
Superconducting qubit
Readout fidelity
Thermal shield coating
IR-absorbing coating
Effective qubit temperature |
| Date: | 2025 |
| Issue Date: | 2025-09-01 16:53:16 (UTC+8) |
| Abstract: | 在發展量子計算技術的過程中，提升讀取保真度（readoutfidelity）是關鍵目標之一。然而，環境中的紅外輻射會引發不必要的態躍遷，從而降低保真度。這類錯誤可分為兩種機率事件，分別為當量子位元被準備於基態卻被測得為激發態的機率P(1|0)，以及準備於激發態卻被測得為基態的機率P(0|1)。
在本論文中，我們在低溫系統之底部裝載（bottom-loading）的屏蔽內側塗上具吸收紅外能力的黑色塗層，比較其對量子位元讀出表現的影響。為進一步理解其背後物理機制，我們亦量測了有效量子位元溫度與相干時間（coherencetimes）隨環境溫度的變化。
我們的研究結果顯示，有黑色塗層的情況下P(1|0)與P(0|1)較低，使讀出保真度由89%提升至93%，證實這種方式確實簡單且有效地降低紅外輻射對單一量子位元的影響，改善我們量測系統的低溫環境。
Achieving high readout fidelity is one of the primary goals in the pursuit of practical quantum computing. However, environmental infrared radiation degrades this fidelity by causing unwanted state transitions. One source of the errors is quantified by P(1|0), the probability of measuring an excited state when a qubit is prepared in the ground state, and P(0|1), the probability of measuring a ground state when prepared in an excited state.
In this thesis, we coated the inner surface of the shielding in a cryogenic bottom-loading system with an IR-absorbing black coating and compared its effect on the qubit readout performance. To further understand the underlying physics, we also studied the temperature dependence of the effective qubit temperature and coherence times.
Our results show that with the black coating, P(1|0) and P(0|1) were lower, leading to an improved readout fidelity from 89% to 93%. This verifies that this method is indeed a simple and effective way to reduce the effect of infrared radiation on a single qubit, improving the cryogenic environment of our measurement system. |
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| Description: | 碩士
國立政治大學
應用物理研究所
112755014 |
| Source URI: | http://thesis.lib.nccu.edu.tw/record/#G0112755014 |
| Data Type: | thesis |
| Appears in Collections: | [應用物理研究所 ] 學位論文
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