本文選題：非慣性系 + 三粒子糾纏態(tài)�。� 參考：《華東師范大學(xué)》2016年碩士論文

【摘要】：人們已經(jīng)對(duì)慣性系下的量子信息問(wèn)題做過(guò)大量的研究,建立了一套較完備的關(guān)于量子信息的理論；而且糾纏態(tài)在量子信息理論里面扮演著重要角色,它被人們認(rèn)為是量子信息處理任務(wù)的主要資源。現(xiàn)在人們進(jìn)行量子信息處理實(shí)驗(yàn)采用的都是一些速度非常大的光子和粒子,并且我們現(xiàn)在所處的世界都是在不停地旋轉(zhuǎn)因而是有加速的,因此我們就要考慮相對(duì)論效應(yīng)會(huì)對(duì)我們的實(shí)驗(yàn)所帶來(lái)的影響。更重要的是,隨著量子理論與廣義相對(duì)論和量子場(chǎng)的結(jié)合日漸緊密,所以研究相對(duì)論框架下的多粒子糾纏態(tài)就變得很重要。首先在學(xué)習(xí)了非慣性系下的兩粒子糾纏態(tài)的基礎(chǔ)之上,我們利用相同的方法來(lái)研究三粒子糾纏隨觀測(cè)者加速的變化情況,經(jīng)過(guò)計(jì)算我們發(fā)現(xiàn)三粒子糾纏會(huì)隨著觀測(cè)者加速度的增加而減少,而且三個(gè)觀測(cè)者都加速時(shí)π-tangle減小最快,但在加速度趨近于無(wú)窮大的情況下它也不會(huì)衰減到零；而這種物理特性對(duì)于標(biāo)量場(chǎng)和狄拉克場(chǎng)都是成立的。然而在加速度趨近于無(wú)窮大的時(shí)候,非慣性系中標(biāo)量場(chǎng)的兩粒子糾纏卻會(huì)衰減到零,因此我們認(rèn)為在處理量子信息任務(wù)時(shí)用三粒子糾纏態(tài)會(huì)比兩粒子糾纏態(tài)更加優(yōu)越。其次,我們研究了量子信息的分布,發(fā)現(xiàn)隨著觀測(cè)者加速度的增加,觀測(cè)者可以獲取的糾纏在逐漸減少,但觀測(cè)者無(wú)法獲取的糾纏卻在逐漸增加。由此可知,在非慣性系中系統(tǒng)量子糾纏的減少是由于Unruh效應(yīng)而使糾纏從Ⅰ區(qū)域進(jìn)入到了Ⅱ區(qū)域,即糾纏進(jìn)入到了物理上因果不相聯(lián)通的區(qū)域而導(dǎo)致的。當(dāng)三個(gè)觀測(cè)者都加速時(shí)糾纏衰減是三種情況下最快的,這是由于糾纏以更快地方式進(jìn)入了觀測(cè)者不可到達(dá)的區(qū)域。最后,我們還研究了互信息和保真度的問(wèn)題,發(fā)現(xiàn)糾纏和互信息都會(huì)重新分布到物理上不可到達(dá)的區(qū)域,信息不會(huì)無(wú)緣無(wú)故地輕易消失；并且,隨著加速度的增加,保真度也逐漸減小；和糾纏的性質(zhì)類似,當(dāng)三個(gè)觀測(cè)者都加速時(shí),保真度減小最快。這也從一定程度上說(shuō)明了糾纏和保真度是有關(guān)聯(lián)的。
[Abstract]:People have done a lot of research on quantum information problem under inertial system, and have established a set of relatively complete theory about quantum information, and entangled state plays an important role in quantum information theory. It is regarded as the main resource of quantum information processing task. Now people are doing quantum information processing experiments using very fast photons and particles, and the world we're living in is constantly spinning and accelerating. So we have to consider the impact of relativistic effects on our experiments. More importantly, with the combination of quantum theory with general relativity and quantum field, the study of multi-particle entangled states in relativistic framework becomes more and more important. Firstly, based on the study of two-particle entangled states in non-inertial systems, we use the same method to study the change of three-particle entanglement with the acceleration of the observer. It is found that the three-particle entanglement decreases with the increase of the acceleration of the observer, and the 蟺 -tangle decreases fastest when all the three observers accelerate, but it does not decay to zero when the acceleration approaches infinity. This physical property is true for both scalar and Dirac fields. However, when the acceleration approaches infinity, the two-particle entanglement of scalar field in the non-inertial system will be reduced to zero, so we think that the three-particle entangled state is better than the two-particle entangled state in dealing with the quantum information task. Secondly, we study the distribution of quantum information. It is found that with the increase of the acceleration of the observer, the entanglement that the observer can obtain is decreasing gradually, but the entanglement that the observer can not get is increasing gradually. It can be concluded that the reduction of quantum entanglement in non-inertial systems is due to the Unruh effect, which leads to entanglement from region I to region 鈪，

本文編號(hào)：1831252