270 research outputs found
Does Anti-Parallel Spin Always Contain more Information ?
We show that the Bloch vectors lying on any great circle is the largest set
S(L) for which the parallel states |n,n> can always be transformed into the
anti-parallel states |n,-n>. Thus more information about the Bloch vector is
not extractable from |n,-n> than from |n,n> by any measuring strategy, for the
Bloch vector belonging to S(L). Surprisingly, the largest set of Bloch vectors
for which the corresponding qubits can be flipped is again S(L). We then show
that probabilistic exact parallel to anti-parallel transformation is not
possible if the corresponding anti-parallel spins span the whole Hilbert space
of the two qubits. These considerations allow us to generalise a conjecture of
Gisin and Popescu (Phys. Rev. Lett. 83 432 (1999)).Comment: Latex, 5 pages, minor revision
Computation on a Noiseless Quantum Code and Symmetrization
Let be the state-space of a quantum computer coupled with the
environment by a set of error operators spanning a Lie algebra
Suppose admits a noiseless quantum code i.e., a subspace annihilated by We show that a universal set of
gates over is obtained by any generic pair of -invariant
gates. Such gates - if not available from the outset - can be obtained by
resorting to a symmetrization with respect to the group generated by Any computation can then be performed completely within the coding
decoherence-free subspace.Comment: One result added, to appear in Phys. Rev. A (RC) 4 pages LaTeX, no
figure
Secure quantum key distribution using squeezed states
We prove the security of a quantum key distribution scheme based on
transmission of squeezed quantum states of a harmonic oscillator. Our proof
employs quantum error-correcting codes that encode a finite-dimensional quantum
system in the infinite-dimensional Hilbert space of an oscillator, and protect
against errors that shift the canonical variables p and q. If the noise in the
quantum channel is weak, squeezing signal states by 2.51 dB (a squeeze factor
e^r=1.34) is sufficient in principle to ensure the security of a protocol that
is suitably enhanced by classical error correction and privacy amplification.
Secure key distribution can be achieved over distances comparable to the
attenuation length of the quantum channel.Comment: 19 pages, 3 figures, RevTeX and epsf, new section on channel losse
Distributed Relay Protocol for Probabilistic Information-Theoretic Security in a Randomly-Compromised Network
We introduce a simple, practical approach with probabilistic
information-theoretic security to mitigate one of quantum key distribution's
major limitations: the short maximum transmission distance (~200 km) possible
with present day technology. Our scheme uses classical secret sharing
techniques to allow secure transmission over long distances through a network
containing randomly-distributed compromised nodes. The protocol provides
arbitrarily high confidence in the security of the protocol, with modest
scaling of resource costs with improvement of the security parameter. Although
some types of failure are undetectable, users can take preemptive measures to
make the probability of such failures arbitrarily small.Comment: 12 pages, 2 figures; added proof of verification sub-protocol, minor
correction
Correlated Errors in Quantum Error Corrections
We show that errors are not generated correlatedly provided that quantum bits
do not directly interact with (or couple to) each other. Generally, this
no-qubits-interaction condition is assumed except for the case where two-qubit
gate operation is being performed. In particular, the no-qubits-interaction
condition is satisfied in the collective decoherence models. Thus, errors are
not correlated in the collective decoherence. Consequently, we can say that
current quantum error correcting codes which correct single-qubit-errors will
work in most cases including the collective decoherence.Comment: no correction, 3 pages, RevTe
Entangling Two Bose-Einstein Condensates by Stimulated Bragg Scattering
We propose an experiment for entangling two spatially separated Bose-Einstein
condensates by Bragg scattering of light. When Bragg scattering in two
condensates is stimulated by a common probe, the resulting quasiparticles in
the two condensates get entangled due to quantum communication between the
condensates via probe beam. The entanglement is shown to be significant and
occurs in both number and quadrature phase variables. We present two methods of
detecting the generated entanglement.Comment: 4 pages, Revte
Universal quantum gates based on a pair of orthogonal cyclic states: Application to NMR systems
We propose an experimentally feasible scheme to achieve quantum computation
based on a pair of orthogonal cyclic states. In this scheme, quantum gates can
be implemented based on the total phase accumulated in cyclic evolutions. In
particular, geometric quantum computation may be achieved by eliminating the
dynamic phase accumulated in the whole evolution. Therefore, both dynamic and
geometric operations for quantum computation are workable in the present
theory. Physical implementation of this set of gates is designed for NMR
systems. Also interestingly, we show that a set of universal geometric quantum
gates in NMR systems may be realized in one cycle by simply choosing specific
parameters of the external rotating magnetic fields. In addition, we
demonstrate explicitly a multiloop method to remove the dynamic phase in
geometric quantum gates. Our results may provide useful information for the
experimental implementation of quantum logical gates.Comment: 9 pages, language revised, the publication versio
Molecular cytogenetic aberrations in patients with multiple myeloma studied by interphase fluorescence in situ hybridization
Background: Multiple myeloma (MM) is an incurable hematological disorder characterized by the accumulation of malignant plasma cells within the bone marrow (BM). The clinical heterogeneity of MM is dictated by the cytogenetic aberrations present in the clonal plasma cells (PCs). Cytogenetic studies in MM are hampered by the hypoproliferative nature of plasma cells in MM. Therefore, fluorescence in situ hybridization (FISH) analysis combined with magnetic-activated cell sorting (MACS) is an attractive alternative for evaluation of numerical and structural chromosomal changes in MM. Methods: Interphase FISH studies with three different specific probes for the regions containing 13q14.3 (D13S319), 14q32 (IGHC/IGHV) and 1q12(CEP1 ) were performed in 48 MM patients. Interphase FISH studies with LSI IGH/CCND1, LSI IGH/FGFR3, and LSI IGH/MAF probes were used to detect t(11;14)(q13;q32), t(4;14)(p16;q32), and t(14;16)(q32;q23) in patients with 14q32 rearrangement. Results: Molecular cytogenetic aberrations were found in 40 (83.3%) of the 48 MM patients. 13 patients (27.1%) simultaneously had 13q deletion/monosomy 13 [del(13q14)], illegitimate IGH rearrangement and chromosome 1 abnormality. Del(13q14) was detected in 21 cases (43.7%), and illegitimate IGH rearrangements in 29 (60.4%) including 6 with t(11;14) and 5 with t(4;14). None of 9 patients with illegitimate IGH rearrangements and without t(11;14) or t(4;14) we detected had t(14;16) (q32;q23). 24 of the 48 MM patients (50%) had chromosome 1 abnormalities. Among 21 patients with del(13q14), 15 patients had Amp1q12;16 had IgH rearrangements. Whereas, among 27 cases without del(13q14), 8 had Amp1q12; 13 had IgH rearrangements. There was a strong association between del(13q14) and Amp1q12(c2 = 8.26, Ρ < 0.01), and between del(13q14) and IgH rearrangement(c2 = 3.88, p < 0.05). Conclusion: 13q deletion/monosomy 13, IGH rearrangement and chromosome 1 abnormality are frequent in MM. They are not randomly distributed, but strongly interconnected. Interphase FISH technique combined with MACS using CD138-specific antibody is a highly sensitive technique at detecting molecular cytogenetic aberrations in MM.ΠΠ±ΠΎΡΠ½ΠΎΠ²Π°Π½ΠΈΠ΅: ΠΌΠ½ΠΎΠΆΠ΅ΡΡΠ²Π΅Π½Π½Π°Ρ ΠΌΠΈΠ΅Π»ΠΎΠΌΠ° (MM) β Π½Π΅ΠΈΠ·Π»Π΅ΡΠΈΠΌΠΎΠ΅ Π³Π΅ΠΌΠ°ΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ΅ Π·Π°Π±ΠΎΠ»Π΅Π²Π°Π½ΠΈΠ΅, Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΠΈΡΡΡΡΠ΅Π΅ΡΡ
Π½Π°ΠΊΠΎΠΏΠ»Π΅Π½ΠΈΠ΅ΠΌ Π·Π»ΠΎΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΡ
ΠΏΠ»Π°Π·ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΊΠ»Π΅ΡΠΎΠΊ Π² ΠΊΠΎΡΡΠ½ΠΎΠΌ ΠΌΠΎΠ·Π³Π΅ (ΠM). ΠΠ»ΠΈΠ½ΠΈΡΠ΅ΡΠΊΠ°Ρ Π³Π΅ΡΠ΅ΡΠΎΠ³Π΅Π½Π½ΠΎΡΡΡ MM ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ΅ΡΡΡ
ΡΠΈΡΠΎΠ³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ Π°Π±Π΅ΡΡΠ°ΡΠΈΡΠΌΠΈ, ΠΏΡΠΈΡΡΡΡΡΠ²ΡΡΡΠΈΠΌΠΈ Π² ΠΊΠ»ΠΎΠ½Π΅ ΠΏΠ»Π°Π·ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΊΠ»Π΅ΡΠΎΠΊ (ΠΠ). Π¦ΠΈΡΠΎΠ³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ
MM ΠΎΡΠ»ΠΎΠΆΠ½Π΅Π½Ρ Π³ΠΈΠΏΠΎΠΏΡΠΎΠ»ΠΈΡΠ΅ΡΠ°ΡΠΈΠ²Π½ΡΠΌΠΈ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΡΠΌΠΈ ΠΠ. Π ΡΠ²ΡΠ·ΠΈ Ρ ΡΡΠΈΠΌ ΡΠ»ΡΠΎΡΠ΅ΡΡΠ΅Π½ΡΠ½Π°Ρ Π³ΠΈΠ±ΡΠΈΠ΄ΠΈΠ·Π°ΡΠΈΡ in situ (FISH)
Π² ΠΊΠΎΠΌΠ±ΠΈΠ½Π°ΡΠΈΠΈ Ρ ΡΠΎΡΡΠΈΡΠΎΠ²ΠΊΠΎΠΉ ΠΊΠ»Π΅ΡΠΎΠΊ, Π°ΠΊΡΠΈΠ²ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΌΠ°Π³Π½ΠΈΡΠ½ΡΠΌΠΈ ΠΏΠΎΠ»ΡΠΌΠΈ (MACS) ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»ΡΠ΅ΡΡΡ Π΄ΠΎΡΡΠΎΠΉΠ½ΠΎΠΉ Π°Π»ΡΡΠ΅ΡΠ½Π°ΡΠΈΠ²ΠΎΠΉ
ΠΌΠ΅ΡΠΎΠ΄Π°ΠΌ ΠΎΡΠ΅Π½ΠΊΠΈ ΡΠΎΡΠ΅ΡΠ½ΡΡ
ΠΈ ΡΡΡΡΠΊΡΡΡΠ½ΡΡ
ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΉ Ρ
ΡΠΎΠΌΠΎΡΠΎΠΌ ΠΏΡΠΈ MM. ΠΠ΅ΡΠΎΠ΄Ρ: ΠΈΠ½ΡΠ΅ΡΡΠ°Π·Π½ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ
FISH Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΡΡΠ΅Ρ
ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΡΠΏΠ΅ΡΠΈΡΠΈΡΠ΅ΡΠΊΠΈΡ
Π·ΠΎΠ½Π΄ΠΎΠ² Π΄Π»Ρ ΡΡΠ°ΡΡΠΊΠΎΠ², ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
13q14.3 (D13S319), 14q32
(IGHC/IGHV) ΠΈ 1q12(CEP1), ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈ Ρ 48 Π±ΠΎΠ»ΡΠ½ΡΡ
Ρ MM. ΠΠ½ΡΠ΅ΡΡΠ°Π·Π½ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ FISH Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ
Π·ΠΎΠ½Π΄ΠΎΠ² LSI IGH/CCND1, LSI IGH/FGFR3 ΠΈ LSI IGH/MAF ΠΏΡΠΈΠΌΠ΅Π½ΡΠ»ΠΈ Π΄Π»Ρ Π΄Π΅ΡΠ΅ΠΊΡΠΈΠΈ t(11;14)(q13;q32), t(4;14)(p16;q32), ΠΈ
t(14;16)(q32;q23) Ρ ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΎΠ² Ρ ΠΏΠ΅ΡΠ΅ΡΡΡΠΎΠΉΠΊΠΎΠΉ 14q32. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ: ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΡΠ΅ ΡΠΈΡΠΎΠ³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ Π°Π±Π΅ΡΡΠ°ΡΠΈΠΈ Π²ΡΡΠ²Π»ΡΠ»ΠΈ Ρ
40 (83,3%) ΠΈΠ· 48 Π±ΠΎΠ»ΡΠ½ΡΡ
Ρ MM. Π£ 13 ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΎΠ² (27,1%) ΠΎΠ΄Π½ΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Ρ 13q Π΄Π΅Π»Π΅ΡΠΈΡ/ΠΌΠΎΠ½ΠΎΡΠΎΠΌΠΈΡ 13 [del(13q14)],
Π°Π½ΠΎΠΌΠ°Π»ΡΠ½Π°Ρ ΠΏΠ΅ΡΠ΅ΡΡΡΠΎΠΉΠΊΠ° IGH ΠΈ Π°Π½ΠΎΠΌΠ°Π»ΠΈΡ Ρ
ΡΠΎΠΌΠΎΡΠΎΠΌΡ 1. Del(13q14) Π΄Π΅ΡΠ΅ΠΊΡΠΈΡΠΎΠ²Π°Π»ΠΈ Π² 21 ΡΠ»ΡΡΠ°Π΅ (43,7%), Π° Π°Π½ΠΎΠΌΠ°Π»ΡΠ½ΡΠ΅
ΠΏΠ΅ΡΠ΅ΡΡΡΠΎΠΉΠΊΠΈ IGH β Π² 29 (60,4%), Π² ΡΠΎΠΌ ΡΠΈΡΠ»Π΅ Ρ 6 ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΎΠ² Ρ t(11;14) ΠΈ 5 Ρ t(4;14). ΠΠΈ Ρ ΠΎΠ΄Π½ΠΎΠ³ΠΎ ΠΈΠ· 9 Π±ΠΎΠ»ΡΠ½ΡΡ
Ρ Π°Π½ΠΎΠΌΠ°Π»ΡΠ½ΡΠΌΠΈ
ΠΏΠ΅ΡΠ΅ΡΡΡΠΎΠΉΠΊΠ°ΠΌΠΈ IGH ΠΈ Π±Π΅Π· t(11;14) ΠΈΠ»ΠΈ t(4;14) Π½Π΅ Π²ΡΡΠ²Π»ΡΠ»ΠΈ ΡΡΠ°Π½ΡΠ»ΠΎΠΊΠ°ΡΠΈΡ t(14;16) (q32;q23). Π£ 24 ΠΈΠ· 48 ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΎΠ² Ρ MM
(50%) ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ»ΠΈ Π°Π½ΠΎΠΌΠ°Π»ΠΈΠΈ Ρ
ΡΠΎΠΌΠΎΡΠΎΠΌΡ 1. Π Π³ΡΡΠΏΠΏΠ΅ ΠΈΠ· 21 Π±ΠΎΠ»ΡΠ½ΡΡ
Ρ del(13q14) Π² 15 ΡΠ»ΡΡΠ°ΡΡ
ΠΈΠΌΠ΅Π»ΠΈΡΡ ΠΏΠ΅ΡΠ΅ΡΡΡΠΎΠΉΠΊΠΈ IgH
Amp1q12;16. Π ΡΠΎ ΠΆΠ΅ Π²ΡΠ΅ΠΌΡ ΠΈΠ· 27 ΡΠ»ΡΡΠ°Π΅Π² Π±Π΅Π· del(13q14) Ρ 8 ΡΠΎΠ΄Π΅ΡΠΆΠ°Π»ΠΈΡΡ Amp1q12; Π² 13 ΡΠ»ΡΡΠ°ΡΡ
ΠΎΡΠΌΠ΅ΡΠ°Π»ΠΈ ΠΏΠ΅ΡΠ΅ΡΡΡΠΎΠΉΠΊΠΈ
IgH. ΠΡΡΠ²Π»Π΅Π½Π° Π²Π·Π°ΠΈΠΌΠΎΡΠ²ΡΠ·Ρ ΠΌΠ΅ΠΆΠ΄Ρ del(13q14) ΠΈ Amp1q12(Ο2
= 8,26, p < 0,01) ΠΈ ΠΌΠ΅ΠΆΠ΄Ρ del(13q14) ΠΈ ΠΏΠ΅ΡΠ΅ΡΡΡΠΎΠΉΠΊΠ°ΠΌΠΈ IgH
(Ο2 = 3,88, p < 0,05). ΠΡΠ²ΠΎΠ΄Ρ: 13q Π΄Π΅Π»Π΅ΡΠΈΡ/ΠΌΠΎΠ½ΠΎΡΠΎΠΌΠΈΡ 13, ΠΏΠ΅ΡΠ΅ΡΡΡΠΎΠΉΠΊΡ IGH ΠΈ Π°Π½ΠΎΠΌΠ°Π»ΠΈΡ Ρ
ΡΠΎΠΌΠΎΡΠΎΠΌΡ 1 ΡΠ°ΡΡΠΎ ΠΎΡΠΌΠ΅ΡΠ°ΡΡ
ΠΏΡΠΈ MM, ΠΏΡΠΈΡΠ΅ΠΌ ΠΈΡ
ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ Π½Π΅ ΡΠ»ΡΡΠ°ΠΉΠ½ΠΎ ΠΈ ΡΠ΅ΡΠ½ΠΎ Π²Π·Π°ΠΈΠΌΠΎΡΠ²ΡΠ·Π°Π½ΠΎ. ΠΠ½ΡΠ΅ΡΡΠ°Π·Π½ΡΠΉ Π°Π½Π°Π»ΠΈΠ· FISH Π² ΠΊΠΎΠΌΠ±ΠΈΠ½Π°ΡΠΈΠΈ Ρ
MACS Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ CD138-ΡΠΏΠ΅ΡΠΈΡΠΈΡΠ½ΡΡ
Π°Π½ΡΠΈΡΠ΅Π» ΡΠ²Π»ΡΠ΅ΡΡΡ Π²ΡΡΠΎΠΊΠΎΡΡΠ²ΡΡΠ²ΠΈΡΠ΅Π»ΡΠ½ΡΠΌ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ Π΄Π΅ΡΠ΅ΠΊΡΠΈΠΈ ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΡΡ
ΡΠΈΡΠΎΠ³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
Π°Π±Π΅ΡΡΠ°ΡΠΈΠΉ ΠΏΡΠΈ MM
Cavity QED and quantum information processing with "hot" trapped atoms
We propose a method to implement cavity QED and quantum information
processing in high-Q cavities with a single trapped but non-localized atom. The
system is beyond the Lamb-Dick limit due to the atomic thermal motion. Our
method is based on adiabatic passages, which make the relevant dynamics
insensitive to the randomness of the atom position with an appropriate
interaction configuration. The validity of this method is demonstrated from
both approximate analytical calculations and exact numerical simulations. We
also discuss various applications of this method based on the current
experimental technology.Comment: 14 pages, 8 figures, Revte
Perturbative Formulation and Non-adiabatic Corrections in Adiabatic Quantum Computing Schemes
Adiabatic limit is the presumption of the adiabatic geometric quantum
computation and of the adiabatic quantum algorithm. But in reality, the
variation speed of the Hamiltonian is finite. Here we develop a general
formulation of adiabatic quantum computing, which accurately describes the
evolution of the quantum state in a perturbative way, in which the adiabatic
limit is the zeroth-order approximation. As an application of this formulation,
non-adiabatic correction or error is estimated for several physical
implementations of the adiabatic geometric gates. A quantum computing process
consisting of many adiabatic gate operations is considered, for which the total
non-adiabatic error is found to be about the sum of those of all the gates.
This is a useful constraint on the computational power. The formalism is also
briefly applied to the adiabatic quantum algorithm.Comment: 5 pages, revtex. some references adde
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