449 research outputs found
Fourier-transform electrospray instrumentation for tandem high-resolution mass spectrometry of large molecules
AbstractMass spectrometry instrumentation providing unit resolution and 10-ppm mass accuracy for molecules larger than 10 kDa was first reported in 1991. This instrumentation has now been improved with a 6.2-T magnet replacing that of 2.8 T, a more efficient vacuum system, ion injection with controlled ion kinetic energies, accumulated ion trapping with an open-cylindrical ion cell, acquisition of 2M data points, and updated electrospray apparatus. The resulting capabilities include resolving power of 5 × 105 for a 29-kDa protein, less than 1-ppm mass measuring error, and dissociation of protein molecular ions to produce dozens of fragment ions whose exact masses can be identified from their mass-to-charge ratio values and isotopic peak spacing
Entanglement of Atomic Qubits using an Optical Frequency Comb
We demonstrate the use of an optical frequency comb to coherently control and
entangle atomic qubits. A train of off-resonant ultrafast laser pulses is used
to efficiently and coherently transfer population between electronic and
vibrational states of trapped atomic ions and implement an entangling quantum
logic gate with high fidelity. This technique can be extended to the high field
regime where operations can be performed faster than the trap frequency. This
general approach can be applied to more complex quantum systems, such as large
collections of interacting atoms or molecules.Comment: 4 pages, 5 figure
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