Quantum information with highly-accessible continuous variable state of light: local oscillators and long-range quantum networks (Conference Presentation)

Abstract

Continuous variables (CV) have become important across all facets of quantum information. From quantum sensing to quantum computing to quantum key distribution, the benefits of deterministic quantum state generation clearly make a compelling case to seek full CV-based quantum information solutions from top to bottom. Long range quantum networks have become of interest for their potential use in all three quantum information scenarios: second generation, distributed quantum sensors over quantum networks, multi-user QKD protocols across long range networks, and distributed quantum computing. However, a long range CV quantum network is impossible without overcoming two major roadblocks. First, to enable quantum state measurement or tomography at network nodes, coherent detection is required, which itself requires sending a powerful local oscillator across the network. Sending such a local oscillator across long distances presents a practical limitation: it cannot coexist on the same network infrastructure as with quantum signals. Second, very long range networks require robust quantum states and third-generation quantum repeaters, which themselves require a nonGaussian gate in the CV world. We will present our recent results on long range CV network generation made possible by feed forward phase recovery schemes for “locally” generated local oscillators. In addition, we will present our work on deterministic quantum network generation with highly accessible, cost effective, integrated sources of quantum entanglement. Finally, in order to enable all applications across true quantum networks, a non Gaussian quantum gate is required. We will outline our proposed cubic phase gate and our experimental progress towards achieving this goal.