The accurate computation of Hamiltonian ground, excited and thermal states on quantum computers stands to impact many problems in the physical and computer sciences, from quantum simulation to ...machine learning. Given the challenges posed in constructing large-scale quantum computers, these tasks should be carried out in a resource-efficient way. In this regard, existing techniques based on phase estimation or variational algorithms display potential disadvantages; phase estimation requires deep circuits with ancillae, that are hard to execute reliably without error correction, while variational algorithms, while flexible with respect to circuit depth, entail additional high-dimensional classical optimization. Here, we introduce the quantum imaginary time evolution and quantum Lanczos algorithms, which are analogues of classical algorithms for finding ground and excited states. Compared with their classical counterparts, they require exponentially less space and time per iteration, and can be implemented without deep circuits and ancillae, or high-dimensional optimization. We furthermore discuss quantum imaginary time evolution as a subroutine to generate Gibbs averages through an analogue of minimally entangled typical thermal states. Finally, we demonstrate the potential of these algorithms via an implementation using exact classical emulation as well as through prototype circuits on the Rigetti quantum virtual machine and Aspen-1 quantum processing unit.The quantum imaginary time evolution and Lanczos algorithms offer a resource-efficient way to compute ground or excited states of target Hamiltonians on quantum computers. This offers promise for quantum simulation on near-term noisy devices.
Summary Mucosal vaccines present several advantages over conventional parenteral vaccines including their ease of administration and low cost, both criteria being priorities for developing countries ...plagued by infectious diseases. A recombinant Lactococcus lactis strain producing the envelope domain III (EDIII) antigen from dengue virus serotype 2 was engineered, and the ability of the live recombinant bacteria to trigger a systemic anti-EDIII IgG antibody response upon nasal or oral administration to BALB/c and C57BL/6 mice was investigated. Results showed that the antibody response depended on the route of administration and on the mouse strain inoculated. Out of six, two and three C57BL/6 mice orally and nasally inoculated with the recombinant bacteria, respectively, displayed anti-EDIII antibody responses higher than that obtained in the mouse group intraperitoneally (i.p.) immunized with heat-inactivated dengue 2 virus. The protective potential of the immune sera was measured using the plaque reduction neutralizing test (PRNT) and results indicated that high anti-EDIII antibody levels did not correlate directly with high neutralizing activities. Immune sera from orally inoculated mice were found the most potent to neutralize in vitro dengue infection with neutralizing antibody activities in some cases higher than that obtained with the immune sera from mice i.p. injected with heat-inactivated virus.
Developing scalable quantum algorithms to study finite-temperature physics of quantum many-body systems has attracted considerable interest due to recent advancements in quantum hardware. However, ...such algorithms in their present form require resources that exceed the capabilities of current quantum computers except for a limited range of system sizes and observables. Here, we report calculations of finite-temperature properties, including energy, static and dynamical correlation functions, and excitation spectra of spin systems with up to four sites on five-qubit IBM Quantum devices. These calculations are performed using the quantum imaginary time evolution (QITE) algorithm and made possible by several algorithmic improvements, including a method to exploit symmetries that reduces the quantum resources required by QITE, circuit optimization procedures to reduce circuit depth, and error-mitigation techniques to improve the quality of raw hardware data. Our work demonstrates that the ansatz-independent QITE algorithm is capable of computing diverse finite-temperature observables on near-term quantum devices.
Simulating complex molecules and materials is an anticipated application of quantum devices. With the emergence of hardware designed to target strong quantum advantage in artificial tasks, we examine ...how the same hardware behaves in modeling physical problems of correlated electronic structure. We simulate static and dynamical electronic structure on a superconducting quantum processor derived from Google’s Sycamore architecture for two representative correlated electron problems: the nitrogenase iron-sulfur molecular clusters and α-ruthenium trichloride, a proximate spin-liquid material. To do so, we simplify the electronic structure into low-energy spin models that fit on the device. With extensive error mitigation and assistance from classical recompilation and simulated data, we achieve quantitatively meaningful results deploying about one fifth of the gate resources used in artificial quantum advantage experiments on a similar architecture. This increases to over half of the gate resources when choosing a model that suits the hardware. Our work serves to convert artificial measures of quantum advantage into a physically relevant setting.
Despite potent insulin‐sensitizing, anti‐inflammatory, and antiatherogenic effects in animal studies, the relationship between serum adiponectin level and coronary artery disease in patients remains ...unclear. We determined the adiponectin profile in a cohort of multiethnic Asian patients with coronary artery disease, and the association between serum adiponectin level and culprit lesion necrotic core (NC) content. Ninety‐four Asian patients (BMI, 25.3 ± 3.7 kg/m2) undergoing percutaneous coronary intervention were recruited. The serum adiponectin level was measured (n = 94), and the baseline virtual histology intravascular ultrasound examination was analyzed (n = 88). The median level of adiponectin was 3.7 µg/ml (interquartile range, 2.8–4.5 µg/ml). The serum adiponectin level was below 10 µg/ml in 90 patients (95.7%) and below 6 µg/ml in 80 patients (85.1%). There was a significant association between ethnicity and serum adiponectin level (P = 0.048). The median adiponectin level was highest among the Chinese, followed by the Malay and the Indians. Serum adiponectin levels were positively associated with culprit lesion NC content. A 1‐µg/ml increase in log adiponectin was associated with a 3.04% (95% confidence interval: 0.33–5.44) increase in culprit lesion NC content. This association remains significant after adjusting for age, sex, ethnicity, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol, and procedural indication. We found a low serum level of adiponectin in Asian patients and a significant ethnic effect on serum adiponectin level. Increased serum adiponectin levels were independently associated with increased culprit lesion NC burden, suggesting a role for adiponectin in modulating coronary plaque vulnerability.
The realization of novel phases of matter on quantum simulators is a topic of intense interest. Digital quantum computers offer a route to prepare topological phases with interactions that do not ...naturally arise in analog quantum simulators. Here, we report the realization of symmetry-protected topological (SPT) phases of a spin-{1/2} Hamiltonian with next-nearest-neighbor hopping on up to 11 qubits on a programmable superconducting quantum processor. We observe clear signatures of the two distinct SPT phases, such as excitations localized to specific edges and finite string order parameters. Our work advances ongoing efforts to realize novel states of matter with exotic interactions on digital near-term quantum computers.
This study investigated the effect of commercially available mouthrinses on the microhardness and wear of composite (Esthet-X, Dentsply) and compomer (Dyract Posterior, Dentsply) restoratives. ...Fifty-four hardness and 36 wear specimens of each material were fabricated and stored in distilled water at 37 degrees C for two weeks. The specimens were then randomly divided into six equal groups and exposed to the following solutions for 24 hours at 37 degrees C: distilled water WC (control); Listerine Original AP (alcohol-containing essential oil/phenolic compound mouthrinse); Colgate Chloropharm AC (alcohol-containing chlorhexidine mouthrinse); Oral B Tooth & Gum Care AF (alcohol-containing fluoride mouthrinse); Oral B Tooth & Gum Care Alcohol Free OF (alcohol free fluoride mouthrinse) and Oral B Sensitive PF (phosphoric acid containing fluoride mouthrinse). After conditioning, the specimens were subjected to hardness testing using a digital microhardness tester (load = 500 gf; dwell time = 15 seconds) and wear testing with a reciprocal compression-sliding system (contact stress = 20 MPa). Wear depth was measured every 1,000 cycles up to 10,000 cycles using profilometry. Data was analyzed using ANOVA/Scheffe's test at significance level 0.05. Dyract was significantly softened by AP, while Esthet-X was significantly softened by AC and AP. The wear resistance of Dyract was significantly reduced after exposure to PF, while the wear resistance of Esthet-X was significantly reduced by AC. The effect of mouthrinses on hardness and wear was material dependent.
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