Circularly polarized luminescence (CPL) switches have attracted widespread attention due to their potential applications in advanced information technologies. However, the design and fabrication of ...solid‐state multiple‐responsive CPL switches remain challenging. Here, through self‐assembly of chiral metal‐organic frameworks (MOFs) and perovskite nanocrystals (NCs), a pair of crystalline enantiomeric (P)‐(+)/(M)‐(−)‐EuMOF⊃MAPbX3 (MA = CH3NH3+, X = Cl−, Br−, I−) adducts is prepared, where the achiral MAPbBr3 perovskite NCs embedded into chiral MOFs inherit the chirality of host MOFs by host‐guest EuBr and PbO coordination bonds, which is demonstrated by synchrotron‐radiation‐based X‐ray absorption spectroscopy. The chiral adducts show enhanced photoluminescence quantum yield (PLQY), good thermal stability of CPL in air, and photoswitchable CPL properties upon altering different UV irradiation. Based on two chiral emission centers and their different characteristics, reversible CPL switches are realized upon a diversity of external stimuli, for example, chemicals (water /CH3NH3Br solution) or temperatures (room temperature/high temperature). Benefiting from the extraordinary stimuli‐responsive and highly reversible switchable CPL, multiple information encryptions and decryptions integrated with CPL, together with a chiroptical logic gate are successfully designed. This work opens a new avenue to generally fabricate solid‐state CPL composite materials and develops new applications based on switchable CPL.
Achiral perovskite nanocrystals (NCs) are embedded in homochiral metal‐organic frameworks (MOFs) for color‐tunable circularly polarized luminescence (CPL) without any ligand passivation. Experimental results indicate that MAPbBr3 NCs adopted a chiral packing in enantiomeric MOFs by EuBr and PbO bonds. The CPL of composites possesses the multiple external‐stimulate responsive reversibility.
The host–guest chemistry of metal–organic frameworks (MOFs) has enabled the derivation of numerous new functionalities. However, intrinsically chiral MOFs (CMOFs) with helical channels have not been ...used to realize crystalline circularly polarized luminescence (CPL) materials. Herein, enantiomeric pairs of MOF crystals are reported, where achiral fluorophores adhere to the inner surface of helical channels via biology‐like H‐bonds and hence inherit the helicity of the host MOFs, eventually amplifying the luminescence dissymmetry factor (glum) of the host l/d‐CMOF (±1.50 × 10−3) to a maximum of ±0.0115 for the composite l/d‐CMOF⊃fluorophores. l/d‐CMOF⊃fluorophores in pairs generate bright color‐tunable CPL and almost ideal white CPL (0.33, 0.32) with a record‐high photoluminescence quantum yield of ≈30%, which are further assembled into a white circularly polarized light‐emitting diode. The present strategy opens a new avenue for propagating the chirality of MOFs to realize universal chiroptical materials.
Achiral‐aggregation‐caused quenching fluorophores are helically arranged in the chiral channels of enantiomeric metal–organic frameworks (MOFs) for color‐tunable and bright white circularly polarized luminescence (photoluminescence quantum yield (PLQY), ≈33%). The experimental results indicate that the helical arrangement is superior to the ET process in the amplification of the luminescence dissymmetry factor. Also, the MOF‐based composites are assembled into a bright white circularly polarized light‐emitting diode (PLQY, ≈30%).
A
bstract
Since the work of Ryu and Takayanagi, deep connections between quantum entanglement and spacetime geometry have been revealed. The negative eigenvalues of the partial transpose of a ...bipartite density operator is a useful diagnostic of entanglement. In this paper, we discuss the properties of the associated
entanglement negativity
and its Rényi generalizations in holographic duality. We first review the definition of the Rényi negativities, which contain the familiar logarithmic negativity as a special case. We then study these quantities in the random tensor network model and rigorously derive their large bond dimension asymptotics. Finally, we study entanglement negativity in holographic theories with a gravity dual, where we find that Rényi negativities are often dominated by bulk solutions that break the replica symmetry. From these replica symmetry breaking solutions, we derive general expressions for Rényi negativities and their special limits including the logarithmic negativity. In fixed-area states, these general expressions simplify dramatically and agree precisely with our results in the random tensor network model. This provides a concrete setting for further studying the implications of replica symmetry breaking in holography.
A
bstract
We use the Einstein-Hilbert gravitational path integral to investigate gravita- tional entanglement at leading order
O
(1
/G
). We argue that semiclassical states prepared by a Euclidean ...path integral have the property that projecting them onto a subspace in which the Ryu-Takayanagi or Hubeny-Rangamani-Takayanagi surface has definite area gives a state with a flat entanglement spectrum at this order in gravitational perturbation theory. This means that the reduced density matrix can be approximated as proportional to the identity to the extent that its Renyi entropies
Sn
are independent of
n
at this order. The
n
-dependence of
Sn
in more general states then arises from sums over the RT/HRT- area, which are generally dominated by different values of this area for each
n
. This provides a simple picture of gravitational entanglement, bolsters the connection between holographic systems and tensor network models, clarifies the bulk interpretation of alge- braic centers which arise in the quantum error-correcting description of holography, and strengthens the connection between bulk and boundary modular Hamiltonians described by Jafferis, Lewkowycz, Maldacena, and Suh.
Regulatory guidelines mandate the strong control of the familywise error rate in confirmatory clinical trials with primary and secondary objectives. Bonferroni tests are one of the popular choices ...for multiple comparison procedures and are building blocks of more advanced procedures. It is usually of interest to find the optimal weighted Bonferroni split for multiple hypotheses. We consider two popular quantities as the optimization objectives, which are the disjunctive power and the conjunctive power. The former is the probability to reject at least one false hypothesis and the latter is the probability to reject all false hypotheses. We investigate the behavior of each of them as a function of different Bonferroni splits, given assumptions about the alternative hypotheses and correlations between test statistics. Under independent tests, unique optimal Bonferroni weights exist; under dependence, optimal Bonferroni weights may not be unique based on a fine grid search. In general, we propose an optimization algorithm based on constrained nonlinear optimization and multiple starting points. The proposed algorithm efficiently identifies optimal Bonferroni weights to maximize the disjunctive or conjunctive power. In addition, we apply the proposed algorithm to graphical approaches, which include many Bonferroni‐based multiple comparison procedures. Utilizing the closed testing principle, we adopt a two‐step approach to find optimal graphs using the disjunctive power. We also identify a class of closed test procedures that optimize the conjunctive power. We apply the proposed algorithm to a case study to illustrate the utility of optimal graphical approaches that reflect study objectives.
The Mn
Cl
mode of red emissive (C
NOH
)
Mn
Cl
·C
H
OH under thermal treatment will be cleaved into MnCl
in the green emissive (C
NOH
)
MnCl
with the departure of ethanol. The rapid conversion of ...luminescence from red to green provides new insight into the luminescence origin and thermal stability of organic-inorganic metal halide hybrids.
A
bstract
We propose a new example of entanglement knitting spacetime together, satisfying a series of checks of the corresponding von Neumann and Renyi entropies. The conjectured dual of de Sitter ...in
d
+ 1 dimensions involves two coupled CFT sectors constrained by residual
d
-dimensional gravity. In the
d
= 2 case, the gravitational constraints and the CFT spectrum are relatively tractable. We identify a finite portion of each CFT Hilbert space relevant for de Sitter. Its maximum energy level coincides with the transition to the universal Cardy behavior for theories with a large central charge and a sparse light spectrum, derived by Hartman, Keller, and Stoica. Significant interactions between the two CFTs, derived previously for other reasons, suggest a maximally mixed state upon tracing out one of the two sectors; we derive this by determining the holographic Renyi entropies. The resulting entanglement entropy matches the Gibbons-Hawking formula for de Sitter entropy, including the numerical coefficient. Finally, we interpret the Gibbons-Hawking horizon entropy in terms of the Ryu-Takayanagi entropy, and explore the time evolution of the entanglement entropy.
•Three-dimensional thermal LB model achieves isotropy of fourth-order error term.•Laminar side-heated convections are simulated with grid up to 2573.•Turbulent RB convections are simulated with 8 ...nodes to resolve boundary layers.
We present numerical simulations of three-dimensional thermal convective flows in a cubic cell at high Rayleigh number using thermal lattice Boltzmann (LB) method. The thermal LB model is based on double distribution function approach, which consists of a D3Q19 model for the Navier-Stokes equations to simulate fluid flows and a D3Q7 model for the convection-diffusion equation to simulate heat transfer. Relaxation parameters are adjusted to achieve the isotropy of the fourth-order error term in the thermal LB model. Two types of thermal convective flows are considered: one is laminar thermal convection in side-heated convection cell, which is heated from one vertical side and cooled from the other vertical side; while the other is turbulent thermal convection in Rayleigh-Bénard convection cell, which is heated from the bottom and cooled from the top. In side-heated convection cell, steady results of hydrodynamic quantities and Nusselt numbers are presented at Rayleigh numbers of 106 and 107, and Prandtl number of 0.71, where the mesh sizes are up to 2573; in Rayleigh-Bénard convection cell, statistical averaged results of Reynolds and Nusselt numbers, as well as kinetic and thermal energy dissipation rates are presented at Rayleigh numbers of 106,3×106, and 107, and Prandtl numbers of 0.7 and 7, where the nodes within thermal boundary layer are around 8. Compared with existing benchmark data obtained by other methods, the present LB model can give consistent results.
A crystalline coordination polymer (CP) photocatalyst (Cu‐RSH) which combines redox‐active copper centers with photoactive rhodamine‐derived ligands remains stable in acid and basic solutions from pH ...2 to 14, and efficiently catalyzes dihydrogen evolution at a maximum rate of 7.88 mmol g−1 h−1 in the absence of a mediator and a co‐catalyst. Cyclic voltammetry, control experiments, and DFT calculations established that copper nodes with open coordination sites and favorable redox potentials, aided by spatially ordered stacking of rhodamine‐based linkers, account for the high catalytic performance of Cu‐RSH. Emission quenching, time‐resolved fluorescence decay, and transient photocurrent experiments disclosed the charge separation and transfer process in the catalytic system. The present study demonstrates the potential of crystalline copper CPs for the practical utilization of light.
On active duty: High activity for the generation of hydrogen has been found on irradiating a crystalline coordination polymer containing redox‐active copper centers and rhodamine‐derived organic linkers with visible light. The ordered stacking of the linkers induced rapid transfer of photogenerated electrons to the copper nodes, which have open coordination sites and a favorable redox potential for reducing protons to dihydrogen.
Circularly polarized luminescence (CPL) originates from the chiral emissive excited states. CPL materials have promising applications in 3D optical displays, encryptions, biological probes, chiral ...photoelectric devices, and CPL switches, most of which require excellent CPL performances including bright luminescence and high luminescence dissymmetry factor (glum) in the agglomerate state. This review systematically summarizes the progress about CPL of aggregate and solid materials, such as organic materials, metal‐organic materials (such as coordination polymers, organic‐inorganic metal halides, metal clusters, and cluster‐assembled materials), the assembled materials by supramolecular interactions, and liquid crystals. We also present the current challenges and a future perspective of chiral emitting agglomerate materials.
In this review, besides the fundamental principles of circularly polarized luminescence (CPL), CPL measurement methods for solid‐state samples and the recent progress of the diverse agglomerate CPL‐emitters, including organic materials, crystalline metal‐organic materials (coordination polymers, organic–inorganic metal halides, metal clusters, and cluster‐assembled materials), supramolecular ensembles, and liquid crystals are summarized. The opportunities and challenges of CPL‐emitters in agglomerate state are presented.
PDF
