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<jats:p> <jats:italic>We propose a class of <jats:italic>n</jats:italic>-variable Boolean functions which can be used to implement quantum secure multiparty computation. We also give an implementation of a special quantum secure multiparty computation protocol. An advantage of our protocol is that only 1 qubit is needed to compute the <jats:italic>n</jats:italic>-tuple pairwise <jats:sc>and</jats:sc> function, which is more efficient comparing with previous protocols. We demonstrate our protocol on the IBM quantum cloud platform, with a probability of correct output as high as 94.63%. Therefore, our protocol presents a promising generalization in realization of various secure multipartite quantum tasks.</jats:italic> </jats:p>

<jats:p> <jats:italic>We present an algorithm for the generalized search problem (searching <jats:italic>k</jats:italic> marked items among <jats:italic>N</jats:italic> items) based on a continuous Hamiltonian and exploiting resonance. This resonant algorithm has the same time complexity <jats:inline-formula> <jats:tex-math><?CDATA $O(\sqrt{N/k})$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>O</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:msqrt> <mml:mrow> <mml:mi>N</mml:mi> <mml:mo>/</mml:mo> <mml:mi>k</mml:mi> </mml:mrow> </mml:msqrt> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpl_37_5_050304_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> as the Grover algorithm. A natural extension of the algorithm, incorporating auxiliary “monitor” qubits, can determine <jats:italic>k</jats:italic> precisely, if it is unknown. The time complexity of our counting algorithm is <jats:inline-formula> <jats:tex-math><?CDATA $O(\sqrt{N})$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>O</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:msqrt> <mml:mi>N</mml:mi> </mml:msqrt> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpl_37_5_050304_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>, similar to the best quantum approximate counting algorithm, or better, given appropriate physical resources.</jats:italic> </jats:p>

<jats:p> <jats:italic>Chemically synthetic nanomotors can consume fuel in the environment and utilize the self-generated concentration gradient to self-propel themselves in the system. We study the collective dynamics of an ensemble of sphere dimers built from linked catalytic and noncatalytic monomers. Because of the confinement from the fuel field and the interactions among motors, the ensemble of dimer motors can self-organize into various nanostructures, such as a radial pattern in the spherical fuel field and a staggered radial pattern in a cylindrical fuel field. The influence of the dimer volume fraction on the self-assembly is also investigated and the formed nanostructures are analyzed in detail. The results presented here may give insight into the application of the self-assembly of active materials.</jats:italic> </jats:p>

<jats:p> <jats:italic>Dark solitons are common topological excitations in a wide array of nonlinear waves. The dark soliton excitation energy is crucial for exploring dark soliton dynamics and is necessarily calculated in a renormalized form due to its existence on a finite background. Despite its tremendous importance and success, the renormalized energy form was at first only suggested with no detailed derivation, and was then “derived” in the grand canonical ensemble. We revisit this fundamental problem and provide an alternative and intuitive derivation of the energy form from the fundamental field energy by utilizing a limiting procedure that conserves number of particles. Our derivation yields the same result, thus putting the dark soliton energy form on a solid basis.</jats:italic> </jats:p>

<jats:p> <jats:italic>Temperature is a fundamental thermodynamic variable for matter. Physical observables are often found to either increase or decrease with it, or show a non-monotonic dependence with peaks signaling underlying phase transitions or anomalies. Statistical field theory has established connection between temperature and time: a quantum ensemble with inverse temperature <jats:italic>β</jats:italic> is formally equivalent to a dynamic system evolving along an imaginary time from 0 to <jats:italic>iβ</jats:italic> in the space one dimension higher. Here we report that a gas of hard-core bosons interacting with a thermal bath manifests an unexpected temperature-periodic oscillation of its macroscopic observables, arising from the microscopic origin of space-time locked translational symmetry breaking and crystalline ordering. Such a temperature crystal, supported by quantum Monte Carlo simulation, generalizes the concept of purely spatial density-wave order to the imaginary time axis for Euclidean action.</jats:italic> </jats:p>

<jats:p> <jats:italic>Employing recently developed magneto-optical trap recoil ion momentum spectroscopy (MOTRIMS) combined with cold atoms, strong laser pulse, and ultrafast technologies, we study momentum distributions of the multiply ionized cold rubidium (Rb) induced by the elliptically polarized laser pulses (35 fs, 1.3 × 10<jats:sup>15</jats:sup> W/cm<jats:sup>2</jats:sup>). The complete vector momenta of Rb<jats:sup> <jats:italic>n</jats:italic>+</jats:sup> ions up to charge state <jats:italic>n</jats:italic> = 4 are recorded with extremely high resolution (0.12 a.u. for Rb<jats:sup>+</jats:sup>). Variations of characteristic multi-bands are displayed in momentum distributions because the ellipticity varies from the linear to circular polarization, are interpreted qualitatively with the classical over-barrier ionization model. Present momentum spectroscopy of cold heavy alkali atoms presents novel strong-field phenomena beyond the noble gases.</jats:italic> </jats:p>

<jats:p> <jats:italic>The trapped ions confined in a surface-electrode trap (SET) could be free from rf heating if they stay at the rf potential null of the potential well. We report our effort to compensate three-dimensionally for the micromotion of a single <jats:sup>40</jats:sup>Ca<jats:sup>+</jats:sup> ion near the rf potential null, which largely suppresses the ion’s heating and thus helps to achieve the cooling of the ion down to 3.4 mK, which is very close to the Doppler limit. This is the prerequisite of the sideband cooling in our SET.</jats:italic> </jats:p>

<jats:p> <jats:italic>We study the superfluid behavior of a population imbalanced ultracold atomic Fermi gases with a short range attractive interaction in a one-dimensional (1D) optical lattice, using a pairing fluctuation theory. We show that, besides widespread pseudogap phenomena and intermediate temperature superfluidity, the superfluid phase is readily destroyed except in a limited region of the parameter space. We find a new mechanism for pair hopping, assisted by the excessive majority fermions, in the presence of continuum-lattice mixing, which leads to an <jats:italic>unusual</jats:italic> constant Bose-Einstein condensate (BEC) asymptote for <jats:italic>T</jats:italic> <jats:sub>c</jats:sub> that is independent of pairing strength. In result, on the BEC side of unitarity, superfluidity, when it exists, may be strongly <jats:italic>enhanced</jats:italic> by population imbalance.</jats:italic> </jats:p>

<jats:p> <jats:italic>A monolithic 0–<jats:italic>f</jats:italic> scheme-based femtosecond optical frequency comb directly driven by a high-power Ti:sapphire laser oscillator is demonstrated. The spectrum covering from 650 nm to 950 nm is generated from the Ti:sapphire oscillator with a repetition rate of 170 MHz. The average output power up to 630 mW is delivered under the pump power of 4.5 W. A 44-dB signal-to-noise ratio (SNR) of the carrier-envelope phase offset (CEO) beat note is achieved under the resolution of 100 kHz and is long-term stabilized to a reference source at 20 MHz. The integrated phase noise (IPN) in the range from 1 Hz to 1 MHz is calculated to be 138 mrad, corresponding to the timing jitter of 63 as at the central wavelength of 790 nm.</jats:italic> </jats:p>

<jats:p> <jats:italic>A dark pulse mode-locked laser is experimentally demonstrated using the indium tin oxide (ITO) coated D-shape fiber as a saturable absorber (SA). Using the polishing wheel technique, a D-shape single mode fiber was fabricated. A 60-nm-thick layer of ITO was deposited over the D-shape fiber using the electron beam deposition method. The SA has a saturation intensity of 40.32 MW/cm<jats:sup>2</jats:sup> and a modulation depth of 3.5%. A stable dark pulse mode-locked laser was observed at a central wavelength of 1559.4 nm with repetition rate 0.98 MHz, pulse width 370 ns and signal-to-noise ratio 61 dB.</jats:italic> </jats:p>