Gigahertz-Clocked Teleportation of Time-Bin Qubits with a Quantum Dot in the Telecommunication C Band
Gigahertz-Clocked Teleportation of Time-Bin Qubits with a Quantum Dot in the Telecommunication C Band
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DOI：
10.1103/physrevapplied.13.054052
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发表时间：
2020-05-21
影响因子：
4.6
通讯作者：
Shields, A. J.
中科院分区：
文献类型：
--
作者：
Anderson, M.;Mueller, T.;Shields, A. J.
隐形传态是量子力学的一个基本概念，在通过量子中继节点扩展量子通信信道范围方面有着重要的应用。为了与光纤网络上的安全量子密钥分发等现实技术兼容，这种中继节点理想情况下应该以千兆赫时钟速率运行，并在1550纳米左右的低损耗电信频段接受时间二进制编码的量子位。在这里，我们证明了InAs-InP液滴外延量子点在1550 nm附近具有亚泊松发射，是实现该技术的理想选择。为了在千兆赫时钟速率下创建必要的按需光子发射，我们开发了一种柔性脉冲光激发方案，并证明了快速驱动条件与低多光子发射速率兼容。我们进一步证明，即使在这些驱动条件下，从双激子级联获得的光子对显示出接近90%的纠缠保真度，与连续波激发下获得的值相当。利用非对称Mach-Zehnder干涉仪和我们的光子源，我们最终构建了一个时间bin量子比特中继，能够接收和发送时间bin编码的光子，并证明了平均隐形传态保真度为0.82 +/- 0.01，比经典极限高出10个标准差以上。
Teleportation is a fundamental concept of quantum mechanics with an important application in extending the range of quantum communication channels via quantum relay nodes. To be compatible with real-world technology such as secure quantum key distribution over fiber networks, such a relay node should ideally operate at gigahertz clock rates and accept time-bin-encoded qubits in the low-loss telecom band around 1550 nm. Here, we show that InAs-InP droplet-epitaxy quantum dots, with their sub-Poissonian emission near 1550 nm, are ideally suited for the realization of this technology. To create the necessary on-demand photon emission at gigahertz clock rates, we develop a flexible-pulsed optical-excitation scheme and demonstrate that the fast driving conditions are compatible with a low multiphoton emission rate. We show further that, even under these driving conditions, photon pairs obtained from the biexciton cascade show an entanglement fidelity close to 90%, comparable to the value obtained under continuous-wave excitation. Using asymmetric Mach-Zehnder interferometers and our photon source, we finally construct a time-bin qubit quantum relay able to receive and send time-bin-encoded photons and demonstrate mean teleportation fidelities of 0.82 +/- 0.01, exceeding the classical limit by more than ten standard deviations.