本文關(guān)鍵詞：朗道齊納轉(zhuǎn)變在超導(dǎo)量子比特中的應(yīng)用　出處：《南京大學(xué)》2016年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 量子計算 超導(dǎo)量子比特 朗道齊納轉(zhuǎn)變 基布爾楚雷克力學(xué) 朗道齊納斯特伯格干涉 量子隨機共振 快速絕熱過程

【摘要】：量子計算和量子信息是利用量子力學(xué)系統(tǒng)進行信息研究的新興熱點。超導(dǎo)量子比特由于其易操作性和強拓展性,正成為目前實現(xiàn)量子計算的最可能的途徑。對于量子比特狀態(tài)的操作的研究,以及利用量子比特進行量子模擬,是量子計算研究的核心之一。朗道齊納轉(zhuǎn)變是一種熟知的量子能級轉(zhuǎn)變的理論,而其在超導(dǎo)量子計算中應(yīng)用尚未被完全發(fā)掘。本文在以下幾個方面對于量子比特的性質(zhì)以及朗道齊納轉(zhuǎn)變在量子計算中的應(yīng)用進行了展現(xiàn)。在基本的量子比特參數(shù)的確定上,我們展示了量子比特能級的確定、退相干時間的測量、拉比震蕩、與天然二能級的耦合等方面的實驗方法和拓展研究,系統(tǒng)研究了單量子比特的性質(zhì)及操作方法。在利用量子比特進行量子模擬方面,我們根據(jù)基布爾楚雷克力學(xué)與朗道齊納轉(zhuǎn)變相關(guān)性的預(yù)言,使用朗道齊納轉(zhuǎn)變來模擬和研究基布爾楚雷克力學(xué)。在三維傳輸子量子比特中,我們觀察到了朗道齊納轉(zhuǎn)變中的絕熱.脈沖近似,量子態(tài)凍結(jié),以及一維伊辛模型中的標度律等現(xiàn)象,驗證了基布爾楚雷克力學(xué)與朗道齊納理論之間的關(guān)聯(lián)。此外,我們研究了強退相干作用下的朗道齊納轉(zhuǎn)變,并開創(chuàng)性的利用能隙重調(diào)的方法研究不同退相干影響下的朗道齊納轉(zhuǎn)變行為。在三維傳輸子比特中,我們利用微波形成有效的微波修飾態(tài)來與量子比特系統(tǒng)的基態(tài)和第一激發(fā)態(tài)構(gòu)成有效的免交叉結(jié)構(gòu),并且利用了微波調(diào)頻的快速可調(diào)性質(zhì),首次在超導(dǎo)三維傳輸子量子比特中觀察到了朗道齊納斯特伯格干涉現(xiàn)象。此外,憑借時間精度為1納秒的時域測量方法,我們進行了在朗道齊納斯特伯格干涉過程中的時間演化的測量,觀察到了量子比特狀態(tài)在干涉過程中的時域演化過程。在量子比特狀態(tài)的操縱方面,利用波形調(diào)制的朗道齊納轉(zhuǎn)變,我們展示了一種有效的進行量子態(tài)的轉(zhuǎn)移和操作的實用的調(diào)頻快速絕熱過程。這種方法可以有效的實現(xiàn)不同能級量子態(tài)之間的轉(zhuǎn)移。相比較于通常的利用共振拉比震蕩的方法,這種方法對操作時間是否精確,對頻率是否共振,以及對功率參數(shù)都不敏感,具有非常高的魯棒性。我們比較了不同波形調(diào)制下的快速絕熱過程的魯棒性和誤差率,展示了特定波形調(diào)制的快速絕熱過程的有效性和可操作性。此外,針對快速絕熱過程是否為有效門操作的疑問,我們研究了調(diào)頻快速絕熱過程針對不同目標門操作的保真度,驗證了其在特定參數(shù)條件下可以成為一種有效量子邏輯門操作的應(yīng)用前景。
[Abstract]:Quantum computation and quantum information is a new hotspot of information research using quantum mechanical systems. The superconducting qubit due to its easy operation and strong expansibility, is becoming the most possible way is to realize quantum computation. Research on quantum bit state of operation, and then simulated by quantum qubit, is one of the core computing study on the quantum Landau Zener transformation is a transformation known as quantum level theory, and its application in superconducting quantum computing has not yet been fully explored. This paper in the following aspects for properties of quantum bit and Landau Zener change the application in quantum computation for the show. In determining the basic parameters of the quantum bit we show, determine the quantum bit level, back measurement, coherent time Rabi oscillation experiment method and natural, and other aspects of the two level of the coupling and extension Study on the properties of the system, and the operation method of single qubit quantum simulation. In the use of quantum bits, we according to Keble Zurek mechanics and Landau Zener transition correlation predictions, using the Landau Zener transition to simulate and study Chulei chocolate. Keble in three transmission sub qubits, we observed adiabatic Landau Zener transition. The impulse approximation, the quantum state of freezing, and one dimensional Ising model scaling phenomenon, verified the relationship between kibble Zurek mechanics and Landau Zener theory. Furthermore, we study the strong decoherence change under the influence of Landau Zener, and groundbreaking use of gap reset different decoherence Landau Zener transition behavior under the influence. In the three-dimensional transmission sub bit, we use microwave microwave modified state effectively with quantum bit system The ground state and the first excited state constitutes free cross structure effectively, and the use of microwave frequency fast tunable properties were observed for the first time Landau Qi Berg Nast interference phenomenon in the superconducting quantum bits in a three-dimensional transmission. In addition, with the accuracy of 1 nanosecond time domain measurement method, we conducted interference measurement evolution process in the time when Landau Berg observed Qi Nast, quantum bit state interference in time domain evolution process. In the manipulation of quantum bit state transition, using waveform modulation Landau Zener, we show an effective transfer and operation of the quantum state of practical FM rapid adiabatic process. This the method can realize the transfer between different levels of quantum states effectively. Compared to the method usually use resonance Rabi oscillation, this method of operation time is fine Indeed, the frequency and power parameters of resonance, are not sensitive, has very high robustness. We compare the robustness and error of rapid adiabatic process under different waveform modulation rate, showing the rapid adiabatic process specific waveform modulation of the effectiveness and operability. In addition, the rapid adiabatic process for the effective operation of doubt, we study the adiabatic process for different target FM fast door operation fidelity, to verify its application prospect can become a kind of effective quantum logic gate operation under certain parameter conditions.

【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：O413
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本文編號：1374334