Approximate Teleportation of an Unknown Atomic-Entangled State with Dissipative Atom-Cavity Resonant Jaynes-Cummings Model

We propose a scheme for approximately and conditionally teleporting an unknown atomic-entangled state in dissipative cavity QED. It is the further development of the scheme of [Phys. Rev. A 69 (2004) 064302], where the cavity mode decay has not been considered and the state teleportated is an unknown atomic state. In this paper, we investigate the influence of the decay on the approximate and conditional teleportation of the unknown atomic-entangled state, which is different from that teleportated in [Phys. Rev. A 69 (2004) 064302] and then give the fidelity of the teleportation, which depends on the cavity mode decay. The scheme may be generalized to not only the teleportation of the cavity-mode-entangled-state by means of a single atom but also the teleportation of the unknown trapped-ion-entangled-state in a linear ion trap.     

Scheme for Deterministic BSM-Free Controlled Teleportation of Unknown Atomic States

We propose a controlled scheme for teleportation of an arbitrary one or two atomic state via a driven QED cavity. The scheme does not involve the joint Bell-state-measurement BSM and the probability of successful teleportation is 1. We show that the original atomic state cannot be perfectly restored by the receiver without all the agents collaborate and classical communication.     

Fast quantum state transfer and entanglement for cavity-coupled many qubits via dark pathways

Quantum state transfer (QST) and entangled state generation (ESG) are important building blocks for modern quantum information processing. To achieve these tasks, convention wisdom is to consult the quantum adiabatic evolution, which is time-consuming, and thus is of low fidelity. Here, using the shortcut to adiabaticity technique, we propose a general method to realize high-fidelity fast QST and ESG in a cavity-coupled many qubits system via its dark pathways, which can be further designed for high-fidelity quantum tasks with different optimization purpose. Specifically, with a proper dark pathway, QST and ESG between any two qubits can be achieved without decoupling the others, which simplifies experimental demonstrations. Meanwhile, ESG among all qubits can also be realized in a single step. In addition, our scheme can be implemented in many quantum systems, and we illustrate its implementation on superconducting quantum circuits. Therefore, we propose a powerful strategy for selective quantum manipulation, which is promising in cavity coupled quantum systems and could find many convenient applications in quantum information processing.     

Guest Solvent‐dependence of the Nanomechanical Response in Substituted Dihydropyrimidinone Crystals

The nanomechanical responses of two crystalline phases of a dihydropyrimidine analogue ( 1 ) were similar irrespective of the presence (or absence) of the guest solvent. In contrast, the mechanical responses of two differently solvated forms of the second related ( 2 ) crystals were significantly different. These contrasting behaviors are rationalized in terms of intermolecular interactions and energy distributions.     

A note on a limit interchange for many-server queues

A connection between open and closed many-server queueing systems is examined. Two limits are considered: (i) the number and reliability of machines (customers) increase simultaneously while the offered load remains constant (Poisson limit), and (ii) the number of machines (customers) and repairmen (servers) increase while the utilization remains close to unity (QED limit). It is argued that the two limits are interchangeable.     

Multi-photon blockade and dressing of the dressed states

Resonant excitation of multi-photon transitions in one-atom cavity QED, from the ground state to an excited dressed state, induce an additional semiclassical Rabi splitting. This “dressing of the dressed states” arises from a multi-photon blockade, where, for sufficiently strong coupling, detunings, brought about by the nonlinearity of the Jaynes-Cummings model, inhibit absorption of additional photons. We show how this behavior is revealed in the spectrum and photon correlations of the quasi-elastically scattered light. Explicit results are presented for the two-photon case.     

A Decoherence-Reduction Scheme by Waveguides in Quantum Information Processing

Based on the result of cavity quantum electrodynamics, we suggest a method, in which the Fabry-Perot cavity or the confocal cavity is replaced by a waveguide with the size comparable to the wavelength of the photon, to reduce decoherence caused by spontaneous emission in quantum information processing, especially in the realization of quantum computation. Since a waveguide has a lowest cutoff frequency while a Fabry-Perot cavity or a confocal cavity has none, the spontaneous emission of excited atoms will be forbidden in an ideal waveguide with an appropriate size. To avoid the influence of the non-ideal conducting walls on the atom in a realistic waveguide, which will lead to decoherence, we suggest that the waveguide should be coated by a thin film of transparent insulating medium. In our method, the quantum information is represented by a multi-level atom or molecule; any two of its levels can be used to represent a qubit in principle. Our method greatly extends the choice of the material to be used in the realization of quantum computation, and it can be used in most schemes to reduce the decoherence caused by spontaneous emission.     

Scheme for Implementing Deutsch-Jozsa Algorithm Using Superconducting Quantum Interference Devices

We propose a physical scheme for implementing the Deutsch-Jozsa algorithm with superconducting quantum interference devices （SQUIDs） in cavity-QED. The scheme is based on SQUID coupled to a single-mode microwave cavity field or classical microwave pluses. The scheme is very simple and may be realizable experimentally.     

基于腔QED技术的量子信息的多方秘密共享

提出了一个基于腔QED技术的量子信息的多方秘密共享方案.该方案不受腔的衰减和热场的影响,并考虑了几种可能偷听下的安全性.     

Block Copolymer Brushes for Completely Decoupled Control of Determinants of Cell–Surface Interactions

The known determinants for cell–surface interactions, comprising biochemical cues, patterns, passivating functionality, and control of tether mechanical properties, are fully decoupled in tailored block copolymer brushes synthesized by surface‐initiated atom transfer radical polymerization. Exploiting sequential polymerization of a passivating underlying polyacrylamide (PAAm) block with defined cross‐linking followed by a second poly(acrylic acid) block, which can be conjugated with a selective adhesion peptide, hierarchically structured brushes that can be micro‐patterned by soft lithography were obtained. The interaction of NIH 3T3 fibroblasts and PaTu 8988t pancreatic tumor cells with brushes that differed only in the stiffness of the hidden PAAm block or only in the peptide ligand, while keeping all other parameters constant, revealing profound differences in cell adhesion and morphology. In particular, cells could only attach well to stiff RGD presenting brushes.