The latest in Quantum Thinking
We demonstrate a modular solid state architecture with deterministic inter-module coupling between four physically separate, interchangeable superconducting qubit integrated circuits.
Learn MoreWe present a novel transmon qubit fabrication technique that yields systematic improvements in T1 coherence times. We fabricate devices using an encapsulation strategy that involves passivating the surface of niobium and thereby preventing the formation of its lossy surface oxide.
Learn MoreWe consider the approximate state estimation of readout-mitigated expectation values, and how to best implement that procedure on the Rigetti quantum computing hardware. We discuss the theoretical aspects involved, providing an explicit computation of the effect of readout error on the estimated expectation values and how to mitigate that effect.
Learn MoreWhat is the optimal circuit depth that provides the best solution? Here, we address this question by investigating an adiabatic circuit that interpolates between the paramagnetic and ferromagnetic ground states of the one-dimensional quantum Ising model.
Learn MoreThe quantum-classical algorithm systematically outperforms its classical counterpart, signaling a quantum enhancement with respect to its guaranteed output quality. Moreover, we observe an absolute performance comparable with the guarantees for a state-of-the-art semi-definite programming method.
Learn MoreIn this work, we demonstrate that any arbitrary qutrit gate can be realized with high fidelity. We generated and tested pulses for a large set of randomly selected arbitrary unitaries on two separate qutrit compatible processors, LLNL Quantum Device and Integration Testbed (QuDIT) standard QPU and Rigetti Aspen-11, achieving an average fidelity around 99 %.
Learn MoreWe introduce two complementary probes of global and relative phase coherence, study how they are affected by measurements of the particle number, and implement them on a superconducting quantum computer by Rigetti.
Learn MoreOur recent work has proposed both unitary and non-unitary state preparation protocols for quantum many-body scar states and their superposition states. Their successful implementation on Aspen M-2 shows a PoC and will serve as a solid starting point for the future study of quantum many-body dynamics.
Trading fidelity for scale enables approximate classical simulators such as matrix product states (MPS) to run quantum circuits beyond exact methods. A control parameter, the so-called bond dimension χ for MPS, governs the allocated computational resources and the output fidelity.
Learn MoreOur central consideration, Hardware Optimized Parity (HOP) gates, achieves stabilizer-type measurements through simultaneous multi-qubit conditional phase accumulation. Despite the multi-body effects that underpin this approach, our estimates of logical faults suggest that this design can be at least as robust to realistic noise as conventional designs.
Learn MoreHere, we consider the QAOA algorithm for solving the paradigmatic Max-Cut problem on different types of graphs. We study the entanglement growth and spread resulting from randomized and optimized QAOA circuits and find that there is a volume-law entanglement barrier between the initial and final states.
Learn MoreWe experimentally demonstrate that two-tone flux modulation can be used to create a continuum of dynamical sweet spots.
Learn MoreWe demonstrate methods to augment conventional convolutional neural networks with quantum-assisted models for generative tasks in global synthetic weather radar.
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