Suppressing decoherence in solid-state quantum information processing

抑制固态量子信息处理中的退相干

• 批准号: EP/E045219/1
• 负责人: Ahsan Nazir
• 金额: $ 32.94万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE045219%2F1
• 关键词: Suppressing; decoherence; solid; state; quantum

Quantum physics describes sub-atomic particles, their interactions with each other, and with external influences such as light. Quantum computation is a potentially ground-breaking technology which applies the laws of quantum physics to computational tasks, requiring an unprecedented level of control over the states of quantum particles, in order to perform algorithms that are impossible on any conventional computer. For example, such computers could provide an unmatched standard of secure communications and efficient database searches.However, in practise, quantum computers are confined to the laboratory and to small numbers of computational elements. Performing the factorisation of 15 (using a register of 7 elements) is state of the art. Although, at first glance, this does not seem a particularly impressive feat (conventional computers have now factorised a 200-digit number), closer examination of the problems inherent in building even a single quantum processor, never mind a register, reveals what a breakthrough this is.Conventional computers perform tasks by storing and processing information encoded in the form of binary bits which take a value of either 1 or 0 (corresponding to logical true or false). Quantum computers encode information in an analogous way (in quantum bits or qubits ). Qubits hold two important advantages over their classical counterparts: they may exist not only as 1 or 0 but as a combination of the two (known as a superposition) - and a register of qubits can share information out between each element due to a property known as entanglement (i.e. the qubits can talk to one another). It is these two properties that lead to the higher efficiency of quantum algorithms. Unfortunately, superposition and entanglement make quantum states extremely fragile. The information they hold is lost very quickly due to contact with the surrounding material of the processor, leading to errors in operation. This is a process known as decoherence. For any large scale quantum computer to be built this fundamental limitation must be overcome.The aim of my planned research is therefore to provide a better understanding of how information is lost from the computational elements of a quantum computer and to propose methods for protecting against such decoherence.

量子物理学描述了亚原子粒子，它们相互的相互作用以及外部影响（例如光）。量子计算是一种潜在的开创性技术，它将量子物理学定律应用于计算任务，需要对量子粒子状态的前所未有的控制水平，以便在任何常规计算机上都无法执行算法。例如，这样的计算机可以提供无与伦比的安全通信和有效数据库搜索的标准。实际上，量子计算机仅限于实验室和少量计算元素。进行15分解（使用7个要素的寄存器）是最新的。 Although, at first glance, this does not seem a particularly impressive feat (conventional computers have now factorised a 200-digit number), closer examination of the problems inherent in building even a single quantum processor, never mind a register, reveals what a breakthrough this is.Conventional computers perform tasks by storing and processing information encoded in the form of binary bits which take a value of either 1 or 0 (corresponding to logical true or false).量子计算机以类似的方式（以量子位或Qubits）进行编码。 Qubits具有两个重要优势，而不是其经典的对应物：它们可能不仅存在为1或0，而且作为两者的组合（称为叠加）的组合 - Qubits的登记库可以在每个元素之间共享信息，这是由于称为纠缠的属性（即，量子量可以互相交谈）。正是这两种特性导致量子算法的效率更高。不幸的是，叠加和纠缠使量子状态极为脆弱。由于与处理器的周围材料接触，他们持有的信息丢失了很快，从而导致运行错误。这是一个被称为破坏的过程。对于要构建的任何大型量子计算机，必须克服此基本限制。因此，我计划的研究的目的是更好地理解量子计算机的计算元素如何丢失信息，并提出保护这种反谐波的方法。

项目成果

Quantum State Tuning of Energy Transfer in a Correlated Environment

• DOI: 10.1021/jz100717d
• 发表时间: 2010-07-15
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY LETTERS
• 影响因子: 5.7
• 作者: Fassioli, Francesca;Nazir, Ahsan;Olaya-Castro, Alexandra
• 通讯作者: Olaya-Castro, Alexandra