12 research outputs found
A bead on a hoop rotating about a horizontal axis: a 1-D ponderomotive trap
We describe a simple mechanical system that operates as a ponderomotive
particle trap, consisting of a circular hoop and a frictionless bead, with the
hoop rotating about a horizontal axis lying in the plane of the hoop. The bead
in the frame of the hoop is thus exposed to an effective sinusoidally-varying
gravitational field. This field's component along the hoop is a zero at the top
and bottom. In the same frame, the bead experiences a time-independent
centrifugal force that is zero at the top and bottom as well. The system is
analyzed in the ideal case of small displacements from the minimum, and the
motion of the particle is shown to satisfy the Mathieu equation. In the
particular case that the axis of rotation is tangential to the hoop, the system
is an exact analog for the rf Paul ion trap. Various complicating factors such
as anharmonic terms, friction and noise are considered. A working model of the
proposed system has been constructed, using a ball-bearing rolling in a tube
along the outside of a section of a bicycle rim. The apparatus demonstrates in
detail the operation of an rf Paul trap by reproducing the dynamics of trapped
atomic ions and illustrating the manner in which the electric potential varies
with time.Comment: Second external review for AJP, 28 pages double spaced, 11 figure
Planar Ion Trap Geometry for Microfabrication
We describe a novel high aspect ratio radiofrequency linear ion trap geometry
that is amenable to modern microfabrication techniques. The ion trap electrode
structure consists of a pair of stacked conducting cantilevers resulting in
confining fields that take the form of fringe fields from parallel plate
capacitors. The confining potentials are modeled both analytically and
numerically. This ion trap geometry may form the basis for large scale quantum
computers or parallel quadrupole mass spectrometers.
PACS: 39.25.+k, 03.67.Lx, 07.75.+h, 07.10+CmComment: 14 pages, 16 figure
T-junction ion trap array for two-dimensional ion shuttling, storage and manipulation
We demonstrate a two-dimensional 11-zone ion trap array, where individual
laser-cooled atomic ions are stored, separated, shuttled, and swapped. The trap
geometry consists of two linear rf ion trap sections that are joined at a 90
degree angle to form a T-shaped structure. We shuttle a single ion around the
corners of the T-junction and swap the positions of two crystallized ions using
voltage sequences designed to accommodate the nontrivial electrical potential
near the junction. Full two-dimensional control of multiple ions demonstrated
in this system may be crucial for the realization of scalable ion trap quantum
computation and the implementation of quantum networks.Comment: 3 pages, 5 figure
ΠΠΎΠ²ΡΡΠ΅Π½ΠΈΠ΅ ΡΡΠΎΠ²Π½Ρ ΡΠ½Π΅ΡΠ³ΠΎΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠ° ΡΠΈΠ½ΡΠ΅Π·Π° Π°ΠΌΠΌΠΈΠ°ΠΊΠ° Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠΊΠΈ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠ°
ΠΠΌΡΠ°ΠΊ Ρ ΠΎΠ΄Π½ΠΎΡ Π· Π½Π΅ΠΎΡΠ³Π°Π½ΡΡΠ½ΠΈΡ
Ρ
ΡΠΌΡΡΠ½ΠΈΡ
ΡΠ΅ΡΠΎΠ²ΠΈΠ½ Π· Π½Π°ΠΉΠ²ΠΈΡΠΎΡ ΡΠ°ΡΡΠΊΠΎΡ Π²ΠΈΡΠΎΠ±Π½ΠΈΡΡΠ²Π° Π² ΡΠ²ΡΡΡ. ΠΡΠΎΡΠ΅Ρ ΡΠΈΠ½ΡΠ΅Π·Ρ Π°ΠΌΡΠ°ΠΊΡ Ρ Π΅Π½Π΅ΡΠ³ΠΎΠ·Π°ΡΡΠ°ΡΠ½ΠΈΠΌ ΡΠ° ΠΏΠΎΡΡΠ΅Π±ΡΡ Π΄Π΅ΡΠ°Π»ΡΠ½ΠΎΠ³ΠΎ Π°Π½Π°Π»ΡΠ·Ρ. Π’Π°ΠΊΠΈΠΉ Π°Π½Π°Π»ΡΠ· Ρ ΠΌΠΎΠΆΠ»ΠΈΠ²ΠΈΠΌ ΡΠ° Π±Π΅Π·ΠΏΠ΅ΡΠ½ΠΈΠΌ Π·Π° Π΄ΠΎΠΏΠΎΠΌΠΎΠ³ΠΎΡ ΠΌΠΎΠ΄Π΅Π»ΡΠ²Π°Π½Π½Ρ ΠΏΡΠΎΡΠ΅ΡΡ. ΠΠ°Π½Π° ΡΡΠ°ΡΡΡ ΡΠΎΠ·Π³Π»ΡΠ΄Π°Ρ ΠΌΠΎΠ΄Π΅Π»ΡΠ²Π°Π½Π½Ρ ΡΠ΅Π°ΠΊΡΠΎΡΡ ΡΠΈΠ½ΡΠ΅Π·Ρ Π°ΠΌΡΠ°ΠΊΡ ΡΠ° Π²ΠΈΠΊΠΎΠ½Π°Π½Π½Ρ Π΅ΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΡ Π½Π°Π΄ ΠΌΠΎΠ΄Π΅Π»Π»Ρ. ΠΠΎΠ΄Π΅Π»Ρ Ρ Π΄ΠΈΠ½Π°ΠΌΡΡΠ½ΠΎΡ, ΡΠΎ Π΄ΠΎΠ·Π²ΠΎΠ»ΡΡ ΠΊΡΠ°ΡΠ΅ Π·ΡΠΎΠ·ΡΠΌΡΡΠΈ ΠΏΡΠΎΡΠ΅Ρ ΡΠΈΠ½ΡΠ΅Π·Ρ ΠΏΡΠΈ ΡΠ°ΠΏΡΠΎΠ²ΡΠΉ Π·ΠΌΡΠ½Ρ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΡΠ² ΠΏΡΠΎΡΠ΅ΡΡ.Ammonia is one of the inorganic chemicals with the highest production rate in the world. The process of ammonia synthesis has a high energy consumption and requires detailed analysis. Such an analysis is feasible and safe using simulation of the process. This paper examines the simulation of the ammonia synthesis reactor and the experiment on the model. The objective of this paper is to develop the basis for a synthesis reactor monitoring tool that can be used to identify the margin to blow-out with respect to current load, catalyst activity, pressure and temperature. For this purpose system dynamics is studied by means of the dynamic modelling. The model is dynamic, and this allows better understanding of the synthesis process in case of the sudden change of the operating parameters.ΠΠΌΠΌΠΈΠ°ΠΊ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΎΠ΄Π½ΠΈΠΌ ΠΈΠ· Π½Π΅ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΡ
Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
Π²Π΅ΡΠ΅ΡΡΠ² Ρ Π²ΡΡΠΎΠΊΠΎΠΉ Π΄ΠΎΠ»Π΅ΠΉ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π° Π² ΠΌΠΈΡΠ΅. ΠΡΠΎΡΠ΅ΡΡ ΡΠΈΠ½ΡΠ΅Π·Π° Π°ΠΌΠΌΠΈΠ°ΠΊΠ° ΡΠ²Π»ΡΠ΅ΡΡΡ ΡΠ½Π΅ΡΠ³ΠΎΠ·Π°ΡΡΠ°ΡΠ½ΡΠΌ ΠΈ ΡΡΠ΅Π±ΡΠ΅Ρ Π΄Π΅ΡΠ°Π»ΡΠ½ΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π°. Π’Π°ΠΊΠΎΠΉ Π°Π½Π°Π»ΠΈΠ· Π²ΠΎΠ·ΠΌΠΎΠΆΠ΅Π½ ΠΈ Π±Π΅Π·ΠΎΠΏΠ°ΡΠ΅Π½ ΠΏΡΠΈ ΠΏΠΎΠΌΠΎΡΡΡ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠΎΡΠ΅ΡΡΠ°. ΠΠ°Π½Π½Π°Ρ ΡΡΠ°ΡΡΡ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°Π΅Ρ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΡΠ΅Π°ΠΊΡΠΎΡΠ° ΡΠΈΠ½ΡΠ΅Π·Π° Π°ΠΌΠΌΠΈΠ°ΠΊΠ° ΠΈ Π²ΡΠΏΠΎΠ»Π½Π΅Π½ΠΈΡ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ° Π½Π°Π΄ ΠΌΠΎΠ΄Π΅Π»ΡΡ. ΠΠΎΠ΄Π΅Π»Ρ ΡΠ²Π»ΡΠ΅ΡΡΡ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ, ΡΡΠΎ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ Π»ΡΡΡΠ΅ ΠΏΠΎΠ½ΡΡΡ ΠΏΡΠΎΡΠ΅ΡΡ ΡΠΈΠ½ΡΠ΅Π·Π° ΠΏΡΠΈ Π²Π½Π΅Π·Π°ΠΏΠ½ΠΎΠΌ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΈ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΠΏΡΠΎΡΠ΅ΡΡΠ°
Sideband cooling and coherent dynamics in a microchip multi-segmented ion trap
Miniaturized ion trap arrays with many trap segments present a promising
architecture for scalable quantum information processing. The miniaturization
of segmented linear Paul traps allows partitioning the microtrap in different
storage and processing zones. The individual position control of many ions -
each of them carrying qubit information in its long-lived electronic levels -
by the external trap control voltages is important for the implementation of
next generation large-scale quantum algorithms.
We present a novel scalable microchip multi-segmented ion trap with two
different adjacent zones, one for the storage and another dedicated for the
processing of quantum information using single ions and linear ion crystals: A
pair of radio-frequency driven electrodes and 62 independently controlled DC
electrodes allows shuttling of single ions or linear ion crystals with
numerically designed axial potentials at axial and radial trap frequencies of a
few MHz. We characterize and optimize the microtrap using sideband spectroscopy
on the narrow S1/2 D5/2 qubit transition of the 40Ca+ ion, demonstrate
coherent single qubit Rabi rotations and optical cooling methods. We determine
the heating rate using sideband cooling measurements to the vibrational ground
state which is necessary for subsequent two-qubit quantum logic operations. The
applicability for scalable quantum information processing is proven.Comment: 17 pages, 11 figure
Ion Trap Networking: Cold, Fast, and Small *
A large-scale ion trap quantum computer will require low-noise entanglement schemes and methods for networking ions between different regions. We report work on both fronts, with the entanglement of two trapped cadmium ions following a phase-insensitive Molmer-Sorensen quantum gate, the entanglement between a single ion and a single photon, and the development of advanced ion traps at the micrometer scale, including the first ion trap integrated on a semiconductor chip. We additionally report progress on the interaction of ultrafast resonant laser pulses with cold trapped ions. This includes fast Rabi oscillations on optical S-P transitions and broadband laser cooling, where the pulse laser bandwidth is much larger than the atomic linewidth. With these fast laser pulses, we also have developed a new method for precision measurement of excited state lifetimes. ION ENTANGLEMENT Local ion entanglement Laser-addressed trapped ions with qubits embedded in long-lived internal hyperfine levels hold significant advantages for quantum information applications One such algorithm is Grover's searching algorithm which searches an unsorted database quadratically faster than any known classical searc
On the transport of atomic ions in linear and multidimensional ion trap arrays
Trapped atomic ions have become one of the most promising architectures for a quantum computer, and current effort is now devoted to the transport of trapped ions through complex segmented ion trap structures in order to scale up to much larger numbers of trapped ion qubits. This paper covers several important issues relevant to ion transport in any type of complex multidimensional rf (Paul) ion trap array. We develop a general theoretical framework for the application of time-dependent electric fields to shuttle laser-cooled ions along any desired trajectory, and describe a method for determining the effect of arbitrary shuttling schedules on the quantum state of trapped ion motion. In addition to the general case of linear shuttling over short distances, we introduce issues particular to the shuttling through multidimensional junctions, which are required for the arbitrary control of the positions of large arrays of trapped ions. This includes the transport of ions around a corner, through a cross or T junction, and the swapping of positions of multiple ions in a laser-cooled crystal. Where possible, we make connections to recent experimental results in a multidimensional T junction trap, where arbitrary 2-dimensional transport was realized