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Experimental demonstration of efficient and selective population transfer and qubit distillation in a rare-earth-metal-ion-doped crystal

Rippe, Lars LU ; Nilsson, M; Kröll, Stefan LU ; Klieber, R and Suter, D (2005) In Physical Review A A71(6).
Abstract
In optically controlled quantum computers it may be favorable to address different qubits using light with different frequencies, since the optical diffraction does not then limit the distance between qubits. Using qubits that are close to each other enables qubit-qubit interactions and gate operations that are strong and fast in comparison to qubit-environment interactions and decoherence rates. However, as qubits are addressed in frequency space, great care has to be taken when designing the laser pulses, so that they perform the desired operation on one qubit, without affecting other qubits. Complex hyperbolic secant pulses have theoretically been shown to be excellent for such frequency-addressed quantum computing [I. Roos and K.... (More)
In optically controlled quantum computers it may be favorable to address different qubits using light with different frequencies, since the optical diffraction does not then limit the distance between qubits. Using qubits that are close to each other enables qubit-qubit interactions and gate operations that are strong and fast in comparison to qubit-environment interactions and decoherence rates. However, as qubits are addressed in frequency space, great care has to be taken when designing the laser pulses, so that they perform the desired operation on one qubit, without affecting other qubits. Complex hyperbolic secant pulses have theoretically been shown to be excellent for such frequency-addressed quantum computing [I. Roos and K. Molmer, Phys. Rev. A 69, 022321 (2004)]-e.g., for use in quantum computers based on optical interactions in rare-earth-metal-ion- doped crystals. The optical transition lines of the rare-earth-metal-ions are inhomogeneously broadened and therefore the frequency of the excitation pulses can be used to selectively address qubit ions that are spatially separated by a distance much less than a wavelength. Here, frequency-selective transfer of qubit ions between qubit states using complex hyperbolic secant pulses is experimentally demonstrated. Transfer efficiencies better than 90% were obtained. Using the complex hyperbolic secant pulses it was also possible to create two groups of ions, absorbing at specific frequencies, where 85% of the ions at one of the frequencies was shifted out of resonance with the field when ions in the other frequency group were excited. This procedure of selecting interacting ions, called qubit distillation, was carried out in preparation for two-qubit gate operations in the rare-earth-metal-ion-doped crystals. The techniques for frequency-selective state-to-state transfer developed here may be also useful also for other quantum optics and quantum information experiments in these long-coherence-time solid-state systems. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
PHASE, PULSES, DESIGN, INVERSION, EXCITATION, STABILIZATION, SPECTROSCOPY, QUANTUM GATE, BROAD-BAND
in
Physical Review A
volume
A71
issue
6
publisher
American Physical Society (APS)
external identifiers
  • WOS:000230275200060
  • Scopus:26944485052
DOI
10.1103/PhysRevA.71.062328
language
English
LU publication?
yes
id
565d7433-139f-480f-8478-4322fba8f11a (old id 586023)
date added to LUP
2007-10-26 16:33:40
date last changed
2017-01-29 04:23:20
@article{565d7433-139f-480f-8478-4322fba8f11a,
  abstract     = {In optically controlled quantum computers it may be favorable to address different qubits using light with different frequencies, since the optical diffraction does not then limit the distance between qubits. Using qubits that are close to each other enables qubit-qubit interactions and gate operations that are strong and fast in comparison to qubit-environment interactions and decoherence rates. However, as qubits are addressed in frequency space, great care has to be taken when designing the laser pulses, so that they perform the desired operation on one qubit, without affecting other qubits. Complex hyperbolic secant pulses have theoretically been shown to be excellent for such frequency-addressed quantum computing [I. Roos and K. Molmer, Phys. Rev. A 69, 022321 (2004)]-e.g., for use in quantum computers based on optical interactions in rare-earth-metal-ion- doped crystals. The optical transition lines of the rare-earth-metal-ions are inhomogeneously broadened and therefore the frequency of the excitation pulses can be used to selectively address qubit ions that are spatially separated by a distance much less than a wavelength. Here, frequency-selective transfer of qubit ions between qubit states using complex hyperbolic secant pulses is experimentally demonstrated. Transfer efficiencies better than 90% were obtained. Using the complex hyperbolic secant pulses it was also possible to create two groups of ions, absorbing at specific frequencies, where 85% of the ions at one of the frequencies was shifted out of resonance with the field when ions in the other frequency group were excited. This procedure of selecting interacting ions, called qubit distillation, was carried out in preparation for two-qubit gate operations in the rare-earth-metal-ion-doped crystals. The techniques for frequency-selective state-to-state transfer developed here may be also useful also for other quantum optics and quantum information experiments in these long-coherence-time solid-state systems.},
  articleno    = {062328},
  author       = {Rippe, Lars and Nilsson, M and Kröll, Stefan and Klieber, R and Suter, D},
  keyword      = {PHASE,PULSES,DESIGN,INVERSION,EXCITATION,STABILIZATION,SPECTROSCOPY,QUANTUM GATE,BROAD-BAND},
  language     = {eng},
  number       = {6},
  publisher    = {American Physical Society (APS)},
  series       = {Physical Review A},
  title        = {Experimental demonstration of efficient and selective population transfer and qubit distillation in a rare-earth-metal-ion-doped crystal},
  url          = {http://dx.doi.org/10.1103/PhysRevA.71.062328},
  volume       = {A71},
  year         = {2005},
}