Experimentelle Untersuchung von Kohärenz und Verschränkung in Josephson-Phasenqubits

约瑟夫森相量子位相干性和纠缠性的实验研究

• 批准号: 5414868
• 负责人: Professor Dr. Alexey V. Ustinov, Ph.D.
• 金额: --
• 依托单位: Physikalisches Institut (PHI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2003
• 资助国家: 德国
• 起止时间: 2002-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5414868?language=en
• 关键词: Experimentelle; Untersuchung; von; Koh; renz

It has been experimentally demonstrated that a variety of micro- and nano-scale superconducting electronic circuits containing Josephson junctions display quantum-coherent dynamics at low temperatures. These circuits are now viewed as very promising candidates to be used as qubits in a future solid state quantum computer. The simplest type of superconduction qubits is the so-called phase qubit, which makes use of the quantum states of a current biased Josephson tunnel junction. These quantum states can be coupled by resonant microwaves to form a controllable two-level systems. We would like to experimentally study individual and coupled Josephson phase qubits. Very recent experiments have shown that these quantum devices can be prepared, controlled and read out by microwave and dc pulses in a manner similar to nuclear spins. Our ultimate goal is to demonstrate coherent manipulation of individual Josephson qubits and create an entanglement between two coupled qubits. In order to achieve this goal, we will study the coupling of Josephson phase qubits to the environment by using tunable interaction between the qubit and on-chip microwave resonators. The relaxation time and the dephasing time of the qubit in the presence of the microwave-tailored environment will be determind. Two Josephsons phase qubits will be coupled capacitively in order to create an entanglement, which will be controlled by dc and microwave pulses. We intend also to study the interaction of the Josephson qubit with the quantized electromagnetic field modes of a high-Q on-chip resonator. We will experimentally characterize the coupling between these two quantum systems and investigate possible mechanisms to create and control their entanglement.

经过实验证明，在低温下，包含约瑟夫森连接的各种微型和纳米级超导电子电路显示量子 - 连锁动力学。现在，这些电路被视为在未来的固态量子计算机中将其用作Qubit的非常有前途的候选人。最简单的超导量点是所谓的相位量保持，它利用当前有偏见的约瑟夫森隧道连接的量子状态。这些量子状态可以通过谐振微波耦合，形成可控的两级系统。我们想在实验中研究个体和耦合约瑟夫森相位量子位。最近的实验表明，这些量子设备可以由微波和直流脉冲以类似于核自旋的方式制备，控制和读取。我们的最终目标是证明对单个约瑟夫森Qubits的连贯操纵，并在两个耦合量子位之间形成纠缠。为了实现这一目标，我们将通过使用量子量和芯片微波谐波谐振器之间的可调相互作用来研究约瑟夫森相位矩阵与环境的耦合。将确定在有微波量的环境中的放松时间和量子量的时间。为了创建一个纠缠，将耦合两个约瑟夫森一相矩形，以由DC和微波脉冲控制。我们还打算研究Josephson Qubit与高Q芯片谐振器的量化电磁场模式的相互作用。我们将通过实验表征这两个量子系统之间的耦合，并研究创建和控制其纠缠的可能机制。