Gapless Higgs Mode in the Fulde-Ferrell-Larkin-Ovchinnikov State of a Superconductor

The Higgs mode associated with amplitude fluctuations of the superconducting gap in uniform superconductors usually is heavy, which makes its excitation and detection difficult. We report on the existence of a gapless Higgs mode in the Fulde-Ferrell-Larkin-Ovchinnikov states. This feature is originated from the Goldstone mode associated with the translation symmetry breaking. The existence of the gapless Higgs mode is demonstrated by using both a phenomenological model and microscopic Bardeen-Cooper-Schrieffer (BCS) theory. The gapless Higgs mode can avoid the decay into other low energy excitations, which renders it stable and detectable.Comment: 11 pages, 3 figures, LA-UR-21-2487

Non-Markovian Fermionic Stochastic Schr\"{o}dinger Equation for Open System Dynamics

In this paper we present an exact Grassmann stochastic Schr\"{o}dinger equation for the dynamics of an open fermionic quantum system coupled to a reservoir consisting of a finite or infinite number of fermions. We use this stochastic approach to derive the exact master equation for a fermionic system strongly coupled to electronic reservoirs. The generality and applicability of this Grassmann stochastic approach is justified and exemplified by several quantum open system problems concerning quantum decoherence and quantum transport for both vacuum and finite-temperature fermionic reservoirs. We show that the quantum coherence property of the quantum dot system can be profoundly modified by the environment memory.Comment: 10.5 pages, 3 figure

Non-Markovian Quantum Trajectories of Many-Body Quantum Open Systems

A long-standing open problem in non-Markovian quantum state diffusion (QSD) approach to open quantum systems is to establish the non-Markovian QSD equations for multiple qubit systems. In this paper, we settle this important question by explicitly constructing a set of exact time-local QSD equations for $N$-qubit systems. Our exact time-local (convolutionless) QSD equations have paved the way towards simulating quantum dynamics of many-body open systems interacting with a common bosonic environment. The applicability of this multiple-qubit stochastic equation is exemplified by numerically solving several quantum open many-body systems concerning quantum coherence dynamics and dynamical control.Comment: 8 pages, 2 figures. manuscript revised and reference update

Myocyte-Specific Overexpressing HDAC4 Promotes Myocardial Ischemia/Reperfusion Injury

Background: Histone deacetylases (HDACs) play a critical role in modulating myocardial protection and cardiomyocyte survivals. However, Specific HDAC isoforms in mediating myocardial ischemia/reperfusion injury remain currently unknown. We used cardiomyocyte-specific overexpression of active HDAC4 to determine the functional role of activated HDAC4 in regulating myocardial ischemia and reperfusion in isovolumetric perfused hearts. Methods: In this study, we created myocyte-specific active HDAC4 transgenic mice to examine the functional role of active HDAC4 in mediating myocardial I/R injury. Ventricular function was determined in the isovolumetric heart, and infarct size was determined using tetrazolium chloride staining. Results: Myocyte-specific overexpressing activated HDAC4 in mice promoted myocardial I/R injury, as indicated by the increases in infarct size and reduction of ventricular functional recovery following I/R injury. Notably, active HDAC4 overexpression led to an increase in LC-3 and active caspase 3 and decrease in SOD-1 in myocardium. Delivery of chemical HDAC inhibitor attenuated the detrimental effects of active HDAC4 on I/R injury, revealing the pivotal role of active HDAC4 in response to myocardial I/R injury. Conclusions: Taken together, these findings are the first to define that activated HDAC4 as a crucial regulator for myocardial ischemia and reperfusion injury

Effects of Selfâ Assembled Monolayer Modification of Nickel Oxide Nanoparticles Layer on the Performance and Application of Inverted Perovskite Solar Cells

Entirely lowâ temperature solutionâ processed (â ¤100â °C) planar pâ iâ n perovskite solar cells (PSCs) offer great potential for commercialization of rollâ toâ roll fabricated photovoltaic devices. However, the stable inorganic holeâ transporting layer (HTL) in PSCs is usually processed at high temperature (200â 500â °C), which is far beyond the tolerant temperature (â ¤150â °C) of rollâ toâ roll fabrication. In this context, inorganic NiOx nanoparticles (NPs) are an excellent candidate to serve as the HTL in PSCs, owing to their excellent solution processability at room temperature. However, the lowâ temperature processing condition is usually accompanied with defect formation, which deteriorates the film quality and device efficiency to a large extent. To suppress this setback, we used a series of benzoic acid selfassembled monolayers (SAMs) to passivate the surface defects of the NiOx NPs and found that 4â bromobenzoic acid could effectively play the role of the surface passivation. This SAM layer reduces the trapâ assisted recombination, minimizes the energy offset between the NiOx NPs and perovskite, and changes the HTL surface wettability, thus enhancing the perovskite crystallization, resulting in more stable PSCs with enhanced power conversion efficiency (PCE) of 18.4â %, exceeding the control device PCE (15.5â %). Also, we incorporated the aboveâ mentioned SAMs into flexible PSCs (Fâ PSCs) and achieved one of the highest PCE of 16.2â % on a polyethylene terephthalate (PET) substrate with a remarkable powerâ perâ weight of 26.9â Wâ gâ 1. This facile interfacial engineering method offers great potential for the largeâ scale manufacturing and commercialization of PSCs.Engineered layers: Lowâ temperature solutionâ processed NiOx nanoparticle film is usually accompanied with defect formation. Here, we find that 4â bromobenzoic acid can form a selfâ assembled monolayer (SAM) on the NiOx film and effectively tune the interfacial properties, resulting in high perovskite solar cells (PSCs) efficiency. Also, we incorporate the aboveâ mentioned SAM into flexible PSCsPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138886/1/cssc201701262_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138886/2/cssc201701262.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138886/3/cssc201701262-sup-0001-misc_information.pd