Undesired coupling to the surrounding environment destroys long-range correlations in quantum processors and hinders coherent evolution in the nominally available computational space. This noise is an outstanding challenge when leveraging the computation power of near-term quantum processors. It has been shown that benchmarking random circuit sampling with cross-entropy benchmarking can provide an estimate of the effective size of the Hilbert space coherently available.
View Article and Find Full Text PDFUnderstanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain's center, [Formula: see text].
View Article and Find Full Text PDFEngineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.
View Article and Find Full Text PDFIntroduction: Human papillomavirus (HPV) is a common sexually transmitted virus that infects over 13 million people every year. Over 80% of sexually active adults will acquire HPV at some point in their lives, which is concerning since certain high-risk strains of HPV can cause six types of cancer. Vaccination against HPV is safe and effective, but despite high vaccine efficacy, vaccination rates are low among both service members and civilians.
View Article and Find Full Text PDFBackground And Objectives: To describe the current landscape of gender and racial diversity among adult neurology residency and fellowship program directors (PDs). Diversity in medicine affects the quality of care provided to a diverse patient population. There are efforts in nearly every field of medicine to increase the diversity of the physician workforce.
View Article and Find Full Text PDFMany quantum algorithms involve the evaluation of expectation values. Optimal strategies for estimating a single expectation value are known, requiring a number of state preparations that scales with the target error ϵ as O(1/ϵ). In this Letter, we address the task of estimating the expectation values of M different observables, each to within additive error ϵ, with the same 1/ϵ dependence.
View Article and Find Full Text PDFSystems of correlated particles appear in many fields of modern science and represent some of the most intractable computational problems in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles. The lack of general solutions for the three-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases.
View Article and Find Full Text PDFInherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the one-dimensional kicked Ising model, which exhibits nonlocal Majorana edge modes (MEMs) with [Formula: see text] parity symmetry.
View Article and Find Full Text PDFMOXIE [Mars Oxygen In Situ Resource Utilization (ISRU) Experiment] is the first demonstration of ISRU on another planet, producing oxygen by solid oxide electrolysis of carbon dioxide in the martian atmosphere. A scaled-up MOXIE would contribute to sustainable human exploration of Mars by producing on-site the tens of tons of oxygen required for a rocket to transport astronauts off the surface of Mars, instead of having to launch hundreds of tons of material from Earth's surface to transport the required oxygen to Mars. MOXIE has produced oxygen seven times between landing in February 2021 and the end of 2021 and will continue to demonstrate oxygen production during night and day throughout all martian seasons.
View Article and Find Full Text PDFQuantum technology promises to revolutionize how we learn about the physical world. An experiment that processes quantum data with a quantum computer could have substantial advantages over conventional experiments in which quantum states are measured and outcomes are processed with a classical computer. We proved that quantum machines could learn from exponentially fewer experiments than the number required by conventional experiments.
View Article and Find Full Text PDFBefore the Perseverance rover landing, the acoustic environment of Mars was unknown. Models predicted that: (1) atmospheric turbulence changes at centimetre scales or smaller at the point where molecular viscosity converts kinetic energy into heat, (2) the speed of sound varies at the surface with frequency and (3) high-frequency waves are strongly attenuated with distance in CO (refs. ).
View Article and Find Full Text PDFEvolution of the US health care system has been punctuated by periods of rapid change. In the coming decades there will be meaningful and potentially disruptive developments in health care delivery mechanisms, the policy environment, and the populations for whom we provide care. Neurologists will need to adapt to changing patient expectations, market dynamics, and regulatory structures to thrive in the future health care environment.
View Article and Find Full Text PDFThe discovery of topological order has revised the understanding of quantum matter and provided the theoretical foundation for many quantum error–correcting codes. Realizing topologically ordered states has proven to be challenging in both condensed matter and synthetic quantum systems. We prepared the ground state of the toric code Hamiltonian using an efficient quantum circuit on a superconducting quantum processor.
View Article and Find Full Text PDFQuantum many-body systems display rich phase structure in their low-temperature equilibrium states. However, much of nature is not in thermal equilibrium. Remarkably, it was recently predicted that out-of-equilibrium systems can exhibit novel dynamical phases that may otherwise be forbidden by equilibrium thermodynamics, a paradigmatic example being the discrete time crystal (DTC).
View Article and Find Full Text PDFWith the rapid development of quantum technology, one of the leading applications that has been identified is the simulation of chemistry. Interestingly, even before full scale quantum computers are available, quantum computer science has exhibited a remarkable string of results that directly impact what is possible in a chemical simulation with any computer. Some of these results even impact our understanding of chemistry in the real world.
View Article and Find Full Text PDFA promising approach to study condensed-matter systems is to simulate them on an engineered quantum platform. However, the accuracy needed to outperform classical methods has not been achieved so far. Here, using 18 superconducting qubits, we provide an experimental blueprint for an accurate condensed-matter simulator and demonstrate how to investigate fundamental electronic properties.
View Article and Find Full Text PDFThe use of quantum computing for machine learning is among the most exciting prospective applications of quantum technologies. However, machine learning tasks where data is provided can be considerably different than commonly studied computational tasks. In this work, we show that some problems that are classically hard to compute can be easily predicted by classical machines learning from data.
View Article and Find Full Text PDFThe Mars 2020 Perseverance rover landing site is located within Jezero crater, a ∼ 50 km diameter impact crater interpreted to be a Noachian-aged lake basin inside the western edge of the Isidis impact structure. Jezero hosts remnants of a fluvial delta, inlet and outlet valleys, and infill deposits containing diverse carbonate, mafic, and hydrated minerals. Prior to the launch of the Mars 2020 mission, members of the Science Team collaborated to produce a photogeologic map of the Perseverance landing site in Jezero crater.
View Article and Find Full Text PDFPhys Rev Lett
September 2020
Quantum algorithms offer a dramatic speedup for computational problems in material science and chemistry. However, any near-term realizations of these algorithms will need to be optimized to fit within the finite resources offered by existing noisy hardware. Here, taking advantage of the adjustable coupling of gmon qubits, we demonstrate a continuous two-qubit gate set that can provide a threefold reduction in circuit depth as compared to a standard decomposition.
View Article and Find Full Text PDFInclusion is the deliberate practice of ensuring that each individual is heard, all personal traits are respected, and all can make meaningful contributions to achieve their full potential. As coronavirus disease 2019 spreads globally and across the United States, we have viewed this pandemic through the lens of equity and inclusion. Here, we discuss how this pandemic has magnified preexisting health and social disparities and will summarize why inclusion is an essential tool to traverse this uncertain terrain and discuss strategies that can be implemented at organizational and individual levels to improve inclusion and address inequities moving forward.
View Article and Find Full Text PDFWith rapid developments in quantum hardware comes a push towards the first practical applications. While fully fault-tolerant quantum computers are not yet realized, there may exist intermediate forms of error correction that enable practical applications. In this work, we consider the idea of post-processing error decoders using existing quantum codes, which mitigate errors on logical qubits using post-processing without explicit syndrome measurements or additional qubits beyond the encoding overhead.
View Article and Find Full Text PDFThe promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor. A fundamental challenge is to build a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here we report the use of a processor with programmable superconducting qubits to create quantum states on 53 qubits, corresponding to a computational state-space of dimension 2 (about 10).
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