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Fabricating ultrathin covalent organic framework (COF) membranes toward high‐permeance molecular separations is highly desired yet challenging. Herein, a polyelectrolyte‐mediated assembly (PMA) strategy is developed to fabricate ultrathin ionic COF membrane for efficient CO2 separation. The PMA strategy allows a facile control over the assembly mode between polyethyleneimine (PEI) and TpPa‐SO3H, yielding PEI‐bridged ultra‐large COF nanosheets which are readily processed into COF membranes with thickness down to 8 nm. The resulting COF membranes exhibit a high CO2 permeances of 1371 GPU and CO2/N2 selectivity of 33 for stimulated flue gas. This PMA strategy may open up a new avenue to fabricating ultrathin 2D material membranes for diverse applications. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are one of the most promising membrane materials for olefin/paraffin separations. However, most of MOF membranes have a thickness over 1 µm, which greatly compromises the permeation flux. While previous studies are focused on increasing crystal nucleus density on the substrates, achieving ultrathin membrane via modulation of the crystal growth is lacking. Herein, an inhibited Ostwald ripening (IOR) strategy is proposed to fabricate ultrathin ZIF‐8 membranes, through incorporating polymer‐based inhibitors into the membrane formula to inhibit the growth process of ZIF‐8 crystals via the metal–organic coordination. The IOR process can be readily tuned by varying the functional groups, molecular weights, and concentrations of the inhibitors, enabling a facile control over the IOR degree and thus the membrane thickness. Consequently, the thickness of ZIF‐8 membranes can be dramatically reduced to 180 nm. The resulting membranes exhibit ultrahigh C3H6/C3H8 separation performance with C3H6 permeance of 386 GPU and C3H6/C3H8 separation factor of 120. It is anticipated that this straightforward and efficient IOR strategy can open a new avenue for the fabrication of ultrathin MOF membranes to tackle many critical molecular separations. [ABSTRACT FROM AUTHOR]

Covalent organic framework (COF) membranes with tunable ordered channels and free organic groups hold great promise in molecular separations owing to the synergy of physical and chemical microenvironments. Herein, we develop a defect engineering strategy to fabricate COF membranes for efficient CO2 separation. Abundant amino groups are in situ generated on the COF nanosheets arising from the missing‐linker defects during the reactive assembly of amine monomer and mixed aldehyde monomers. The COF nanosheets are assembled to fabricate COF membranes. Amino groups, as the CO2 facilitated transport carriers, along with ordered channels endow COF membrane with high CO2 permeances exceeding 300 GPU and excellent separation selectivity of 80 for CO2/N2, and 54 for CO2/CH4 mixed gas under humidified state. Our defect engineering strategy offers a facile approach to generating free organic functional groups in COF membranes and other organic framework membranes for diverse chemical separations. [ABSTRACT FROM AUTHOR]

Ionic covalent organic framework nanosheets (iCOFNs) with long‐range ordered and mono‐dispersed ionic groups hold great potential in many advanced applications. Considering the inherent drawbacks of oil–water biphase method, herein, we explore an oil–water–oil triphase method based on phase engineering strategy for the bottom‐up synthesis of iCOFNs. The middle water phase serves as a confined reaction region, and the two oil phases are reservoirs for storing and supplying monomers to the water phase. A large aqueous space and low monomer concentration lead to the anisotropic gradual growth of iCOFNs into few‐layer thickness, large lateral size, and high crystallinity. Notably, the resulting three cationic and anionic iCOFNs exhibit ultra‐high aspect ratios of up to 20,000. We further demonstrate their application potential by processing into ultrathin defect‐free COF membranes for efficient biogas separation. Our triphase method may offer an alternative platform technology for the synthesis and innovative applications of iCOFNs. [ABSTRACT FROM AUTHOR]

Invariant‐based shortcuts to adiabaticity (IB‐STA) approach is demonstrated to speed up the coherent population transfer of a three‐level quantum system on a superconducting circuit. Compared with the conventional stimulated Raman adiabatic passage (STIRAP), the scheme can achieve the same high transfer efficiency with evolution time reduced by 5.96 times. The final transfer efficiency of the scheme is measured to be 98.2±2.2%, which is mainly decoherence limited. Further, the robustness of the scheme is experimentally characterized, which is superior to the time‐optimal resonant Rabi scheme under systematic pulse amplitude error. Therefore, the approach provides an alternative approach to realize high‐fidelity state manipulation and preparation for weakly coupled Λ‐ or Ξ‐type quantum systems. [ABSTRACT FROM AUTHOR]

In quantum information processing, it is necessary to transfer quantum state between different systems. Herein, a scheme to transfer quantum state using multi‐passage Landau–Zener–Stückelberg interferometry in three superconducting qubits is proposed. A periodic triangle waveform quickly drives the system across the energy level anticrossing multiple times, inducing multiphoton Rabi oscillations. Using the 0‐photon Rabi oscillations, the dynamical quantum state transfer with probability close to 100% is realized. The fidelity of the state transfer is insensitive to local distortion of the driving waveform. This scheme can be extended to a system where multiple qubits are coupled to a frequency‐tunable qubit, as a quantum medium. It provides a useful tool for scalable quantum computing. [ABSTRACT FROM AUTHOR]