652 research outputs found
Nonadiabatic noncyclic geometric quantum computation in Rydberg atoms
Nonadiabatic geometric quantum computation (NGQC) has been developed to
realize fast and robust geometric gate. However, the conventional NGQC is that
all of the gates are performed with exactly the sameamount of time, whether the
geometric rotation angle is large or small, due to the limitation of cyclic
condition. Here, we propose an unconventional scheme, called nonadiabatic
noncyclic geometric quantum computation(NNGQC), that arbitrary single- and
two-qubit geometric gate can be constructed via noncyclic non-Abeliangeometric
phase. Consequently, this scheme makes it possible to accelerate the
implemented geometric gatesagainst the effects from the environmental
decoherence. Furthermore, this extensible scheme can be applied invarious
quantum platforms, such as superconducting qubit and Rydberg atoms.
Specifically, for single-qubit gate,we make simulations with practical
parameters in neutral atom system to show the robustness of NNGQC and also
compare with NGQC using the recent experimental parameters to show that the
NNGQC can significantly suppress the decoherence error. In addition, we also
demonstrate that nontrivial two-qubit geometric gate can berealized via
unconventional Rydberg blockade regime within current experimental
technologies. Therefore, ourscheme provides a promising way for fast and robust
neutral-atom-based quantum computation.Comment: 6 pages, 6 figures. Published visio
Error-Resilient Floquet Geometric Quantum Computation
We proposed a new geometric quantum computation (GQC) scheme, called Floquet
GQC (FGQC), where error-resilient geometric gates based on periodically driven
two-level systems can be constructed via a new non-Abelian geometric phase
proposed in a recent study [V. Novi\^{c}enko \textit{et al}, Phys. Rev. A 100,
012127 (2019) ]. Based on Rydberg atoms, we gave possible implementations of
universal single-qubit gates and a nontrivial two-qubit gate for FGQC. By using
numerical simulation, we evaluated the performance of the FGQC Z and X gates in
the presence of both decoherence and a certain kind of systematic control
error. The gate fidelities of the Z and X gates are . The numerical results provide evidence that
FGQC gates can achieve fairly high gate fidelities even in the presence of
noise and control imperfection. In addition, we found FGQC is robust against
global control error, both analytical demonstration and numerical evidence were
given. Consequently, this study makes an important step towards robust
geometric quantum computation.Comment: 12 pages,7 figure
Chloroplastic ATP Synthase Alleviates Photoinhibition of Photosystem I in Tobacco Illuminated at Chilling Temperature
Chloroplastic ATP synthase plays a significant role in the regulation of proton motive force (pmf) and proton gradient (ΔpH) across the thylakoid membranes. However, the regulation of chloroplastic ATP synthase at chilling temperature and its role in photoprotection are little known. In our present study, we examined the chlorophyll fluorescence, P700 signal, and electrochromic shift signal at 25°C, and 6°C in tobacco (Nicotiana tabacum L. cv. Samsun). Although photosynthetic electron flow through both PSI and PSII were severely inhibited at 6°C, non-photochemical quenching and P700 oxidation ratio were largely increased. During the photosynthetic induction under high light, the formation of pmf at 6°C was similar to that at 25°C. However, the ΔpH was significantly higher at 6°C, owing to the decreased activity of chloroplastic ATP synthase (gH+). During illumination at 6°C and high light, a high ΔpH made PSI to be highly oxidized, preventing PSI from photoinhibition. These results indicate that the down-regulation of gH+ is critical to the buildup of ΔpH at low temperature, adjusting the redox state of PSI, and thus preventing photodamage to PSI. Our findings highlight the importance of chloroplastic ATP synthase in photoprotection at chilling temperature
Circadian Clock Genes in the Metabolism of Non-alcoholic Fatty Liver Disease
Non-alcoholic fatty liver disease (NAFLD) is a common disease, which is characterized by the accumulation of triglycerides in the hepatocytes without excess alcohol intake. Circadian rhythms can participate in lipid, glucose, and cholesterol metabolism and are closely related to metabolism seen in this disease. Circadian clock genes can modulate liver lipid metabolism. Desynchrony of circadian rhythms and the influences imparted by external environmental stimuli can increase morbidity. By contrast, synchronizing circadian rhythms can help to alleviate the metabolic disturbance seen in NAFLD. In this review, we have discussed the current research connections that exist between the circadian clock and the metabolism of NAFLD, and we have specifically focused on the key circadian clock genes, Bmal1, Clock, Rev-Erbs, Rors, Pers, Crys, Nocturnin, and DECs
Benchmarking reconstructive spectrometer with multi-resonant cavities
Recent years have seen the rapid development of miniaturized reconstructive
spectrometers (RSs), yet they still confront a range of technical challenges,
such as bandwidth/resolution ratio, sensing speed, and/or power efficiency.
Reported RS designs often suffer from insufficient decorrelation between
sampling channels, which results in limited compressive sampling efficiency, in
essence, due to inadequate engineering of sampling responses. This in turn
leads to poor spectral-pixel-to-channel ratios (SPCRs), typically restricted at
single digits. So far, there lacks a general guideline for manipulating RS
sampling responses for the effectiveness of spectral information acquisition.
In this study, we shed light on a fundamental parameter from the compressive
sensing theory - the average mutual correlation coefficient v - and provide
insight into how it serves as a critical benchmark in RS design with regards to
the SPCR and reconstruction accuracy. To this end, we propose a novel RS design
with multi-resonant cavities, consisting of a series of partial reflective
interfaces. Such multi-cavity configuration offers an expansive parameter
space, facilitating the superlative optimization of sampling matrices with
minimized v. As a proof-of-concept demonstration, a single-shot, dual-band RS
is implemented on a SiN platform, tailored for capturing signature spectral
shapes across different wavelength regions, with customized photonic crystal
nanobeam mirrors. Experimentally, the device demonstrates an overall operation
bandwidth of 270 nm and a <0.5 nm resolution with only 15 sampling channels per
band, leading to a record high SPCR of 18.0. Moreover, the proposed
multi-cavity design can be readily adapted to various photonic platforms. For
instance, we showcase that by employing multi-layer coatings, an
ultra-broadband RS can be optimized to exhibit a 700 nm bandwidth with an SPCR
of over 100
1-(4-Chlorophenyl)-3-phenyl-1H-pyrazol-5(4H)-one
In the crystal of the title compound, C15H11ClN2O, the molecules are linked by C—H⋯O and weak C—H⋯π interactions. The chlorophenyl and phenyl rings are twisted with respect to the central pyrazolone ring, making dihedral angles of 18.23 (8) and 8.35 (8)°, respectively. The N—N and C=O bond lengths are comparable to those reported for pyrazolone compounds
Near-Term Quantum Computing Techniques: Variational Quantum Algorithms, Error Mitigation, Circuit Compilation, Benchmarking and Classical Simulation
Quantum computing is a game-changing technology for global academia, research
centers and industries including computational science, mathematics, finance,
pharmaceutical, materials science, chemistry and cryptography. Although it has
seen a major boost in the last decade, we are still a long way from reaching
the maturity of a full-fledged quantum computer. That said, we will be in the
Noisy-Intermediate Scale Quantum (NISQ) era for a long time, working on dozens
or even thousands of qubits quantum computing systems. An outstanding
challenge, then, is to come up with an application that can reliably carry out
a nontrivial task of interest on the near-term quantum devices with
non-negligible quantum noise. To address this challenge, several near-term
quantum computing techniques, including variational quantum algorithms, error
mitigation, quantum circuit compilation and benchmarking protocols, have been
proposed to characterize and mitigate errors, and to implement algorithms with
a certain resistance to noise, so as to enhance the capabilities of near-term
quantum devices and explore the boundaries of their ability to realize useful
applications. Besides, the development of near-term quantum devices is
inseparable from the efficient classical simulation, which plays a vital role
in quantum algorithm design and verification, error-tolerant verification and
other applications. This review will provide a thorough introduction of these
near-term quantum computing techniques, report on their progress, and finally
discuss the future prospect of these techniques, which we hope will motivate
researchers to undertake additional studies in this field.Comment: Please feel free to email He-Liang Huang with any comments,
questions, suggestions or concern
The Score Model Containing Chinese Medicine Syndrome Element of Blood Stasis Presented a Better Performance Compared to APRI and FIB-4 in Diagnosing Advanced Fibrosis in Patients with Chronic Hepatitis B
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