Abstracts

Visualizing Super Current in Josephson Junctions 

Elizabeth Park, Graduate Student, Yacoby lab

Electrical resistance measurement is a widely used and effective method to characterize topological and correlated phases in quantum materials. However, resistance measurements have limitations – they average over distances given by the contact separation and are therefore insensitive to features smaller than the size and spacing of the electrical contacts. Additionally, they are incapable of providing details in cases where the underlying resistance is zero such as superconductors. To circumvent these limitations, local mapping of current flow can be used to uncover hidden phases in exotic materials. In this talk I will present recent results of current flow patterns in a Josephson junction using nitrogen vacancy (NV) centers in diamond. Our measurements reveal intricate current flow patterns that change rapidly as the external flux or DC current are varied. Our results uncover ground state configurations that can be switched with subtle changes in the drive current, and provide insight to the origin of the superconducting diode effect. Our observed current changes to the current flow patterns are invisible in a conventional transport experiment thus highlighting the importance of our imaging capabilities.

Probing Quantum Floating Phases in Rydberg Atom Arrays 

Sergio Cantu, Senior Research Scientist, QuEra

Quantum floating phases, long proposed in commensurate-incommensurate transitions, have lacked experimental confirmation. In this study, we experimentally observe a quantum floating phase using Rydberg arrays with ladder geometries, employing up to 92 qubits. Our analysis reveals that 1+1 dimensions with rectangular arrays of Rydberg atoms have an extended region in the phase diagram where the floating phase appears. Through meticulous comparisons of measurements across phases and system sizes, incommensurate order within the floating phase is observed Unique bitstring distributions characterize each phase, emphasizing the critical state's distinctive nature. Our findings hint at potential applications of ladder-shaped atom arrays in quantum simulation research, advancing our understanding of quantum phases and paving the way for further exploration in Rydberg dynamics using neutral atom arrays.

Unlocking the Potential of Quantum-Classical Processing  

Yonatan Cohen, co-founder & CTO, Quantum Machines 

In recent years, it has become increasingly clear that realizing the potential of Quantum Computers would require tight quantum-classical integration, in particular to overcome the high error rate in various manners. In this talk, we will dive into the considerations for building quantum-classical architectures and present the latest progress and developments in the field. We will present our latest results from Google-Quantum Machine’s collaboration to perform long-range quantum teleportation, demonstrating the need of and the advantage of tight, real-time quantum-classical integration. We will discuss the importance of defining quantum-classical processing requirements and benchmarks. Finally, we will introduce NVIDIA-Quantum Machine’s DGX Quantum, an architecture built to scale up ultra-low latency quantum-classical machines towards practical implementations of quantum error correction.