We study the Bose-Einstein condensate (BEC) in a 3-D toroidal Mexican hat trap. By changing the parameters of the potential, or the number of bosons, it is possible to modify strongly the density profile of the BEC. We consider the ground state properties for positive and negative scattering length and calculate the spectrum elementary excitations. We also discuss the macroscopic phase coherenc...

Despite the ubiquitous nature of misfolded intermediates in RNA folding, little is known about their physical properties or the folding transitions that allow them to continue folding productively. Folding of the Tetrahymena group I ribozyme includes sequential accumulation of two intermediates, termed I(trap) and misfolded (M). Here, we probe the structure and folding transition of I(trap) and...

where abg = 63.0 a0 is the background scattering length, ∆ = 0.88 G is the width, and B0 is the center of the resonance near 154.7 G. As we already pointed out in Ref. [2], the optical trap induces a differential light shift between the atom pair state and the molecular state. This leads to a lightinduced shift of the FR center. For the experiments presented in the main text, we use a near-infr...

We investigate in detail the effects of a QND vibrational number measurement made on single ions in a recently proposed measurement scheme for the vibrational state of a register of ions in a linear rf trap [C. D’Helon and G. J Milburn, Phys. Rev. A 54, 5141 (1996)]. The performance of a measurement shows some interesting patterns which are closely related to searching. Typeset using REVTEX 1

We report the formation of a tunable single DNA molecule trap near a solid-state nanopore in an electrolyte solution under conditions where an electric force and a pressure-induced viscous flow force on the molecule are nearly balanced. Trapped molecules can enter the pore multiple times before escaping the trap by passing through the pore or by diffusing away. Statistical analysis of many indi...

The tapered SiO2 nanofiber for the trap [1] is drawn from a conventional optical fiber in a hydrogen-oxygen flame [2–4]. Fig. SM1 shows the radius r(z) as a function of axial coordinate z from SEM measurements for a set of 8 fiber tapers. The central region ∆z yields an average radius r(z) = 215 ± 10 nm for −3 < z < 3 mm, as shown in (b). The red curve is a theoretical calculation for r(z) [2] ...

Entanglement [1] is one of the essential and most puzzling features of quantum mechanics. It is also the basic ingredient and resource of quantum informa­ tion processing: quantum teleportation [2, 3], quan­ tum dense coding [4], quantum cryptography [5], and quantum computation [6] are just a few examples of the possibilities offered by sharing quantum en­ tanglement. Recently, for example, it...

NMDA receptors are highly expressed in the CNS and are involved in excitatory synaptic transmission, as well as synaptic plasticity. Given that overstimulation of NMDA receptors can cause cell death, it is not surprising that these channels are under tight control by a series of inhibitory extracellular ions, including zinc, magnesium, and H+. We studied the inhibition by extracellular protons ...