Observation of many-body Fock space dynamics in two dimensions

Quantum many-body simulation provides a straightforward way to understand fundamental physics and connect with quantum information applications. However, suffering from exponentially growing Hilbert space size, characterization in terms of few-body probes in real space is often insufficient to tackle challenging problems such as quantum critical behavior and many-body localization (MBL) in higher dimensions. Here, we experimentally employ a new paradigm on a superconducting quantum processor, exploring such elusive questions from a Fock space view: mapping the many-body system onto an unconventional Anderson model on a complex Fock space network of many-body states. By observing the wave packet propagating in Fock space and the emergence of a statistical ergodic ensemble, we reveal a fresh picture for characterizing representative many-body dynamics: thermalization, localization, and scarring. In addition, we observe a quantum critical regime of anomalously enhanced wave packet width and deduce a critical point from the maximum wave packet fluctuations, which lend support for the two-dimensional MBL transition in finite-sized systems. Our work unveils a new perspective of exploring many-body physics in Fock space, demonstrating its practical applications on contentious MBL aspects such as criticality and dimensionality. Moreover, the entire protocol is universal and scalable, paving the way to finally solve a broader range of controversial many-body problems on future larger quantum devices.Comment: 8 pages, 4 figures + supplementary informatio

Radioisotope results for ²¹⁰Pb and ¹³⁷Cs.

<p><b>(A)</b>²¹⁰Pb activity (Bq kg^-1), <b>(B)</b>²¹⁰Pb-inferred chronologies (yr) and <b>(C)</b>¹³⁷Cs activity (Bq kg^-1) plotted against mass depth (g cm^-2) for SAF-1 core. <b>(D)</b>²¹⁰Pb activity, <b>(E)</b>²¹⁰Pb-inferred chronologies and <b>(F)</b>¹³⁷Cs activity plotted against mass depth for BAF-1 core. Error bars represent 1 standard deviation (SD) from counting uncertainty.</p

A Novel PZT Pump with Built-in Compliant Structures

Different to the traditionally defined valved piezoelectric (PZT) pump and valveless PZT pump, two groups of PZT pumps with built-in compliant structures&mdash;with distances between the free ends of 0.2 mm (Group A) and 0 mm (Group B)&mdash;were designed, fabricated, and experimentally tested. This type of pump mainly contains a chamber 12 mm in diameter and 1.1 mm in height, a PZT vibrator, and two pairs of compliant structures arranged on the flowing channel. The flow-resistance differences between these two groups of PZT pumps were theoretically and experimentally verified. The relationships between the amplitude, applied voltage and frequency of the PZT vibrators were obtained experimentally, with results illustrating that the amplitude linearly and positively correlates with the voltage, while nonlinearly and negatively correlating to the frequency. The flow rate performance of these two groups was experimentally tested from 110&ndash;160 Vpp and 10&ndash;130 Hz. Results showed that the flow rate positively correlates to the voltage, and the optimum flow rate frequency centers around 90 Hz for Group A and 80 Hz for Group B, respectively. The flow rate performances of Group B were further measured from 60&ndash;100 Hz and 170&ndash;210 Vpp, and obtained optimal flow rates of 3.6 mL/min at 210 Vpp and 80 Hz when ignoring the siphon-caused backward flow rate. As the compliant structures are not prominently limited by the channel&rsquo;s size, and the pump can be minimized by Micro-electromechanical Systems (MEMS) processing methods, it is a suitable candidate for microfluidic applications like closed-loop cooling systems and drug delivery systems

Sediment rate (SR, cm yr^-1) and mass accumulation rate (MAR, g cm^-2 yr^-1) plotted against age determined from ²¹⁰Pb (calendar year AD) of two sediment cores (SAF-1 and BAF-1) in Yancheng coastal wetland, China.

<p>Sediment rate (SR, cm yr^-1) and mass accumulation rate (MAR, g cm^-2 yr^-1) plotted against age determined from ²¹⁰Pb (calendar year AD) of two sediment cores (SAF-1 and BAF-1) in Yancheng coastal wetland, China.</p

Historical trend of BC flux and its potential source.

<p><b>(A)</b> Variation of BC flux from 1860 to 2013 reconstructed from two sediment cores (SAF-1 and BAF-1) in Yancheng coastal wetland, China. An obvious peaking period of BC flux is marked by red bar (last 20 years). Error bars represent the standard deviation (SD) of the mean of three parallel samples. <b>(B)</b> Variations of social and economic development indicators in Jiangsu province including gross domestic product (GDP), gross industrial production, total energy consumption and total sown area [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129680#pone.0129680.ref049" target="_blank">49</a>] and total carbon emission (1995–2010) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129680#pone.0129680.ref050" target="_blank">50</a>].</p

Photos of core sampling.

<p><b>(A)</b> A photo showing the sampling site scene at Yancheng coastal wetland and core sampling in the field. <b>(B)</b> and <b>(C)</b> Photos showing the sediment cores of SAF-1 and BAF-1. PVC pipes were cut in half to show the lithologic character in the laboratory.</p

Depth variations of physicochemical parameters of two sediment cores (SAF-1 and BAF-1) in Yancheng coastal wetland, China.

<p><b>(A)</b> Water content (%). <b>(B)</b> Dry bulk density (g cm^-3). <b>(C)</b> Mass magnetic susceptibility (10⁻⁸ m³ kg^-1).</p

Location of sampling site.

<p><b>(A)</b> China map showing the location of Yancheng city in Jiangsu province. <b>(B)</b> Yancheng map showing the National Nature Reserve area and the sampling site.</p

Depth variations of black carbon (BC, mg g^-1) of two sediment cores (SAF-1 and BAF-1) in Yancheng coastal wetland, China.

<p>An obvious peaking section of BC content is marked by red bar (the surface 15 cm). Error bars represent the standard deviation (SD) of the mean of three parallel samples.</p

Chlorogenic acid protects against cholestatic liver injury in rats

AbstractThe aim of this study was to investigate the protective effect of chlorogenic acid (CA) on liver injury caused by bile duct ligation (BDL), as well as the potential mechanism. Permanent bile duct ligation induced liver injury was evaluated by liver index, liver function and pathological observation. Oral administration of CA for 3 weeks markedly attenuated liver swelling and fibrosis. Blood biochemistry results revealed that CA decreased alanine transaminase, aspartate aminotransferase, alkaline phosphatase, total bilirubin, direct bilirubin and total bile acid. PCR analysis indicated that collagen I, collagen III, transforming growth factor and vascular endothelial growth factor mRNA were increased markedly by BDL treatment but these increases were suppressed by CA. Additionally, CA effectively alleviated the expression of α-smooth muscle actin induced by BDL. Taken together, our data indicate that CA can efficiently inhibit BDL-induced liver injury in rats, which is a candidate drug for preventing liver injury against cholestasis