107 research outputs found
The time as an emergent property of quantum mechanics, a synthetic description of a first experimental approach
The "problem of time" in present physics substantially consists in the fact
that a straightforward quantization of the general relativistic evolution
equation and constraints generates for the Universe wave function the
Wheeler-De Witt equation, which describes a static Universe. Page and Wootters
considered the fact that there exist states of a system composed by entangled
subsystems that are stationary, but one can interpret the component subsystems
as evolving: this leads them to suppose that the global state of the universe
can be envisaged as one of this static entangled state, whereas the state of
the subsystems can evolve. Here we synthetically present an experiment, based
on PDC polarization entangled photons, that allows showing with a practical
example a situation where this idea works, i.e. a subsystem of an entangled
state works as a "clock" of another subsystem
Bell measurements as a witness of a dualism in entanglement
We show how a property of dualism, which can exist in the entanglement of
identical particles, can be tested in the usual photonic Bell measurement
apparatus with minor modifications. Two different sets of coincidence
measurements on the same experimental setup consisting of a Hong-Ou-Mandel
interferometer demonstrate how the same two-photon state can emerge
entanglement in the polarization or the momentum degree of freedom depending on
the dynamical variables used for labeling the particles. Our experiment
demonstrates how the same source can be used as both a polarization entangled
state, as well as a dichotomic momentum entangled state shared between distant
users Alice and Bob in accordance to which sets of detectors they access. When
the particles become distinguishable by letting the information about one of
the variables to be imprinted in yet another (possibly inaccessible) system or
degree of freedom, the feature of dualism is expected to vanish. We verify this
feature by polarization decoherence (polarization information in environment)
or arrival time difference, which both respectively destroy one of the dual
forms of entanglement.Comment: 5 pages, 4 figure
Exploring Quantum Correlations from Discord to Entanglement
Quantum correlations represent a fundamental tool for studies ranging from basic science to quantum technologies. Different non-classical correlations have been identified and studied, as entanglement and discord. In this Paper we explore experimentally the rich geometry of polarization Bell-diagonal states. By taking advantage of the statistical method of generation, the values of entanglement and discord along different trajectories in the space of the parameters of density matrix have been measured. The effects of sudden death of entanglement and complete "freeze" of discord were investigated in order to detect the domains with different domination of one type of quantum correlation against to other. A geometric interpretation for each considered phenomena is addressed. The observed good agreement between experiment and theory for all investigated trajectories ensures the reliability of this method
Statistical Estimation of Quantum Tomography Protocols Quality
A novel operational method for estimating the efficiency of quantum state
tomography protocols is suggested. It is based on a-priori estimation of the
quality of an arbitrary protocol by means of universal asymptotic fidelity
distribution and condition number, which takes minimal value for better
protocol. We prove the adequacy of the method both with numerical modeling and
through the experimental realization of several practically important protocols
of quantum state tomography
Anisotropically high entanglement of biphotons generated in spontaneous parametric down conversion
We show that the wave packet of a biphoton generated via spontaneous
parametric down conversion is strongly anisotropic. Its anisotropic features
manifest themselves very clearly in comparison of measurements performed in two
different schemes: when the detector scanning plane is perpendicular or
parallel to the plane containing the crystal optical axis and the laser axis.
The first of these two schemes is traditional whereas the second one gives rise
to such unexpected new results as anomalously strong narrowing of the biphoton
wave packet measured in the coincidence scheme and very high degree of
entanglement. The results are predicted theoretically and confirmed
experimentally
Direct experimental observation of nonclassicality in ensembles of single photon emitters
In this work we experimentally demonstrate for the first time a recently
proposed criterion adressed to detect nonclassical behavior in the fluorescence
emission of ensembles of single-photon emitters. In particular, we apply the
method to study clusters of NV centres in diamond observed via
single-photon-sensitive confocal microscopy. Theoretical considerations on the
behavior of the parameter at any arbitrary order in presence of poissonian
noise are presented and, finally, the opportunity of detecting manifold
coincidences is discussed
ΠΠΠΠΠΠ‘-ΠΠΠΠΠΠ¬ Π ΠΠ Π ΠΠΠ¬ Π Π ΠΠΠ ΠΠΠΠ’ΠΠ ΠΠΠΠΠΠΠ¦ΠΠΠΠΠΠ ΠΠΠΠΠ’ΠΠΠ (ΠΠΠΠΠΠ ΠΠΠ Π£ΠΠΠΠΠ«Π₯ ΠΠΠΠ¦ΠΠΠ¦ΠΠ)
Nowadays, the development of an effective innovation policy is one of the priority issues of the socioeconomic development of Russia and many other countries. However, despite the efforts made, not all of them succeeded in its solution. In Russia, like in a number of other states, the expert community continue to searchΒ or effective ways to influence microeconomic entities and, above all, businesses that would yield an adequate response. Therefore, any attempt to reveal structures which, when affected, would lead to the increase in the innovative activity of commercial organizations, are not only of theoretical but also of great practical interest. The paper analyzes proposals of foreign authors on the solution of this problem. The foreign approaches under study are focused on the recognition of the business model as a special component of commercial organizations. Its specifics should be taken into account in development and implementation of the state innovation policy in relation to business. As part of a general critical analysis of the approaches, the author summarized and systematized the existing views on the contents of business models, their types and relationships with innovations in organizations. At present, there is no common understanding in the literature that the choice of particular types of business models determining different sources of innovative activity in response to the corresponding state policy requires a prudent attitude and preliminary clarification of a number of additional conditions. The most significant of these include the type of a business model, the stability of its reproduction and position in the industry markets. The conclusions made in the paper require that new important areas of theoretical research into the domestic economy should be developed. They should be directed towards the determination of business model types in different economic sectors, their stability and development of a corresponding state innovation course with respect to them. Along with above, these conclusions lay the foundations for practical efforts to implement innovative strategies developed for enterprizes with different types of business models.Π Π½Π°ΡΡΠΎΡΡΠ΅Π΅ Π²ΡΠ΅ΠΌΡ ΡΡΠ΅Π΄ΠΈ ΠΏΠ΅ΡΠ²ΠΎΠΎΡΠ΅ΡΠ΅Π΄Π½ΡΡ
ΠΏΡΠΎΠ±Π»Π΅ΠΌ ΠΎΠ±ΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎ-ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠ°Π·Π²ΠΈΡΠΈΡ Π ΠΎΡΡΠΈΠΈ ΠΈ ΠΌΠ½ΠΎΠ³ΠΈΡ
Π΄ΡΡΠ³ΠΈΡ
ΡΡΡΠ°Π½ ΡΡΠΎΠΈΡ Π²ΠΎΠΏΡΠΎΡ ΠΎ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠΊΠ΅ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΠΉ ΠΈΠ½Π½ΠΎΠ²Π°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠΈ. ΠΠ΄Π½Π°ΠΊΠΎ Π½Π΅ΡΠΌΠΎΡΡΡ Π½Π° ΠΏΡΠ΅Π΄ΠΏΡΠΈΠ½ΠΈΠΌΠ°Π΅ΠΌΡΠ΅ ΡΡΠΈΠ»ΠΈΡ, ΠΌΠ½ΠΎΠ³ΠΈΠΌ ΠΏΠΎΠΊΠ° Π½Π΅ ΡΠ΄Π°Π΅ΡΡΡ ΡΠ΅ΡΠΈΡΡ Π΅Π³ΠΎ. Π Π½Π°ΡΠ΅ΠΉ ΡΡΡΠ°Π½Π΅, ΠΊΠ°ΠΊ ΠΈ Π² ΡΠ΅Π»ΠΎΠΌ ΡΡΠ΄Π΅ Π΄ΡΡΠ³ΠΈΡ
Π³ΠΎΡΡΠ΄Π°ΡΡΡΠ², ΡΡΠ΅Π½ΡΠ΅ ΠΈ ΠΏΡΠ°ΠΊΡΠΈΠΊΠΈ ΠΏΡΠΎΠ΄ΠΎΠ»ΠΆΠ°ΡΡ Π²Π΅ΡΡΠΈ ΠΏΠΎΠΈΡΠΊΠΈ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΈΠ²Π½ΡΡ
ΡΠΏΠΎΡΠΎΠ±ΠΎΠ² Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ Π½Π° ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΡΠ±ΡΠ΅ΠΊΡΡ, ΠΈ Π² ΠΏΠ΅ΡΠ²ΡΡ ΠΎΡΠ΅ΡΠ΅Π΄Ρ Π½Π° Π±ΠΈΠ·Π½Π΅Ρ, ΠΊΠΎΡΠΎΡΡΠ΅ Π±Ρ Π²ΡΠ·Π²Π°Π»ΠΈ Π°Π΄Π΅ΠΊΠ²Π°ΡΠ½ΡΠΉ ΠΎΡΠ²Π΅Ρ. ΠΠΎΡΡΠΎΠΌΡ ΠΏΠΎΠΏΡΡΠΊΠΈ Π²ΡΡΠ²ΠΈΡΡ ΡΠ΅ ΡΡΡΡΠΊΡΡΡΡ, Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π½Π° ΠΊΠΎΡΠΎΡΡΠ΅ ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΠ»ΠΎ Π±Ρ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΠ΅ ΠΈΠ½Π½ΠΎΠ²Π°ΡΠΈΠΎΠ½Π½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΊΠΎΠΌΠΌΠ΅ΡΡΠ΅ΡΠΊΠΈΡ
ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΠΉ, ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»ΡΡΡ Π½Π΅ ΡΠΎΠ»ΡΠΊΠΎ ΡΠ΅ΠΎΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΠΉ, Π½ΠΎ ΠΈ Π±ΠΎΠ»ΡΡΠΎΠΉ ΠΏΡΠ°ΠΊΡΠΈΡΠ΅ΡΠΊΠΈΠΉ ΠΈΠ½ΡΠ΅ΡΠ΅Ρ. ΠΠ½Π°Π»ΠΈΠ·Ρ ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½ΠΈΠΉ Π·Π°ΡΡΠ±Π΅ΠΆΠ½ΡΡ
Π°Π²ΡΠΎΡΠΎΠ² ΠΏΠΎ ΡΠ΅ΡΠ΅Π½ΠΈΡ ΡΡΠΎΠ³ΠΎ Π²ΠΎΠΏΡΠΎΡΠ° ΠΏΠΎΡΠ²ΡΡΠ΅Π½Π° Π½Π°ΡΡΠΎΡΡΠ°Ρ ΡΡΠ°ΡΡΡ. Π ΡΠ΅Π½ΡΡΠ΅ Π²Π½ΠΈΠΌΠ°Π½ΠΈΡ ΠΈΡΡΠ»Π΅Π΄ΡΠ΅ΠΌΡΡ
ΠΏΠΎΠ΄Ρ
ΠΎΠ΄ΠΎΠ² ΠΈΠ½ΠΎΡΡΡΠ°Π½Π½ΡΡ
ΡΡΠ΅Π½ΡΡ
Π»Π΅ΠΆΠ°Π»ΠΎ ΠΏΡΠΈΠ·Π½Π°Π½ΠΈΠ΅ Π±ΠΈΠ·Π½Π΅Ρ-ΠΌΠΎΠ΄Π΅Π»ΠΈ ΠΊΠ°ΠΊ ΡΠΏΠ΅ΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠ»Π΅ΠΌΠ΅Π½ΡΠ° ΠΊΠΎΠΌΠΌΠ΅ΡΡΠ΅ΡΠΊΠΈΡ
ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΠΉ, ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠΈ ΠΊΠΎΡΠΎΡΠΎΠ³ΠΎ ΡΠ»Π΅Π΄ΡΠ΅Ρ Π½Π΅ΠΏΡΠ΅ΠΌΠ΅Π½Π½ΠΎ ΡΡΠΈΡΡΠ²Π°ΡΡ ΠΏΡΠΈ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠΊΠ΅ ΠΈ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ Π³ΠΎΡΡΠ΄Π°ΡΡΡΠ²Π΅Π½Π½ΠΎΠΉ ΠΈΠ½Π½ΠΎΠ²Π°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠΈ Π² ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠΈ Π±ΠΈΠ·Π½Π΅ΡΠ°. Π ΡΠ°ΠΌΠΊΠ°Ρ
ΠΎΠ±ΡΠ΅Π³ΠΎ ΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π° ΠΏΠΎΠ΄Ρ
ΠΎΠ΄ΠΎΠ² Π°Π²ΡΠΎΡ ΠΎΠ±ΠΎΠ±ΡΠΈΠ» ΠΈ ΡΠΈΡΡΠ΅ΠΌΠ°ΡΠΈΠ·ΠΈΡΠΎΠ²Π°Π» ΠΈΠΌΠ΅ΡΡΠΈΠ΅ΡΡ Π²Π·Π³Π»ΡΠ΄Ρ Π½Π° ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ Π±ΠΈΠ·Π½Π΅Ρ-ΠΌΠΎΠ΄Π΅Π»Π΅ΠΉ, ΠΈΡ
ΡΠΈΠΏΡ ΠΈ ΡΠ²ΡΠ·ΠΈ Ρ ΠΈΠ½Π½ΠΎΠ²Π°ΡΠΈΡΠΌΠΈ Π² ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΡΡ
. Π Π½Π°ΡΡΠΎΡΡΠ΅Π΅ Π²ΡΠ΅ΠΌΡ ΠΏΠΎ Π΄Π°Π½Π½ΠΎΠΌΡ Π²ΠΎΠΏΡΠΎΡΡ Π² ΡΠΏΠ΅ΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ Π»ΠΈΡΠ΅ΡΠ°ΡΡΡΠ΅ Π΅ΡΠ΅ Π½Π΅ ΡΠ»ΠΎΠΆΠΈΠ»ΠΎΡΡ ΠΎΠ΄Π½ΠΎΠ·Π½Π°ΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ½ΠΈΠΌΠ°Π½ΠΈΡ, ΡΡΠΎ ΠΎΠ±ΡΠ°ΡΠ΅Π½ΠΈΠ΅ ΠΊ ΡΠ°Π·Π½ΡΠΌ ΡΠΈΠΏΠ°ΠΌ Π±ΠΈΠ·Π½Π΅Ρ-ΠΌΠΎΠ΄Π΅Π»Π΅ΠΉ ΠΊΠ°ΠΊ ΠΎΠ±ΡΡΠ»ΠΎΠ²Π»ΠΈΠ²Π°ΡΡΠΈΠΌ ΡΠ°Π·Π½ΡΠ΅ ΠΈΡΡΠΎΡΠ½ΠΈΠΊΠΈ ΠΈΠ½Π½ΠΎΠ²Π°ΡΠΈΠΎΠ½Π½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ Π² ΠΎΡΠ²Π΅Ρ Π½Π° ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΡΡ Π³ΠΎΡΡΠ΄Π°ΡΡΡΠ²Π΅Π½Π½ΡΡ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΡ ΡΡΠ΅Π±ΡΠ΅Ρ ΠΎΡΠΌΠΎΡΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠ³ΠΎ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ ΠΈ ΠΏΡΠ΅Π΄Π²Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠ³ΠΎ Π²ΡΡΡΠ½Π΅Π½ΠΈΡ ΡΠ΅Π»ΠΎΠ³ΠΎ ΡΡΠ΄Π° Π΄ΠΎΠΏΠΎΠ»Π½ΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΡΠ»ΠΎΠ²ΠΈΠΉ. Π Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΠΌ ΠΈΠ· Π½ΠΈΡ
ΠΎΡΠ½ΠΎΡΡΡΡΡ ΡΠΈΠΏ Π±ΠΈΠ·Π½Π΅Ρ-ΠΌΠΎΠ΄Π΅Π»ΠΈ, ΡΡΠ°Π±ΠΈΠ»ΡΠ½ΠΎΡΡΡ Π΅Π΅ Π²ΠΎΡΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π° ΠΈ ΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΡ Π½Π° ΠΎΡΡΠ°ΡΠ»Π΅Π²ΡΡ
ΡΡΠ½ΠΊΠ°Ρ
. Π‘Π΄Π΅Π»Π°Π½Π½ΡΠ΅ Π² ΡΡΠ°ΡΡΠ΅ Π²ΡΠ²ΠΎΠ΄Ρ Π·Π°ΡΡΠ°Π²Π»ΡΡΡ ΠΎΠ±ΡΠ°ΡΠΈΡΡΡΡ ΠΊ Π½ΠΎΠ²ΡΠΌ Π²Π°ΠΆΠ½ΡΠΌ Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡΠΌ ΡΠ΅ΠΎΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ ΠΎΡΠ΅ΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΠΉ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ, ΠΊΠ°ΡΠ°ΡΡΠΈΡ
ΡΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΡΠΈΠΏΠΎΠ² Π±ΠΈΠ·Π½Π΅Ρ-ΠΌΠΎΠ΄Π΅Π»Π΅ΠΉ Π² ΡΠ°Π·Π½ΡΡ
ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ΅ΠΊΡΠΎΡΠ°Ρ
, ΠΈΡ
ΡΡΡΠΎΠΉΡΠΈΠ²ΠΎΡΡΠΈ ΠΈ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠΊΠΈ ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΠ΅Π³ΠΎ Π³ΠΎΡΡΠ΄Π°ΡΡΡΠ²Π΅Π½Π½ΠΎΠ³ΠΎ ΠΈΠ½Π½ΠΎΠ²Π°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΊΡΡΡΠ° ΠΏΠΎ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ ΠΊ Π½ΠΈΠΌ. ΠΠΌΠ΅ΡΡΠ΅ Ρ ΡΠ΅ΠΌ ΡΡΠΈ Π²ΡΠ²ΠΎΠ΄Ρ Π·Π°ΠΊΠ»Π°Π΄ΡΠ²Π°ΡΡ ΠΎΡΠ½ΠΎΠ²Ρ ΠΈ Π΄Π»Ρ ΠΏΡΠ°ΠΊΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΡΠΈΠ»ΠΈΠΉ ΠΏΠΎ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΠΈΠ½Π½ΠΎΠ²Π°ΡΠΈΠΎΠ½Π½ΡΡ
ΡΡΡΠ°ΡΠ΅Π³ΠΈΠΉ, ΡΠ°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π½ΡΡ
Π² ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠΈ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ² Ρ ΡΠ°Π·Π½ΡΠΌΠΈ ΡΠΈΠΏΠ°ΠΌΠΈ Π±ΠΈΠ·Π½Π΅Ρ-ΠΌΠΎΠ΄Π΅Π»Π΅ΠΉ
Native NIR-emitting single colour centres in CVD diamond
Single-photon sources are a fundamental element for developing quantum
technologies, and sources based on colour centres in diamonds are among the
most promising candidates. The well-known NV centres are characterized by
several limitations, thus few other defects have recently been considered. In
the present work, we characterize in detail native efficient single colour
centres emitting in the near infra-red in both standard IIa single-crystal and
electronic-grade polycrystalline commercial CVD diamond samples. In the former
case, a high-temperature annealing process in vacuum is necessary to induce the
formation/activation of luminescent centres with good emission properties,
while in the latter case the annealing process has marginal beneficial effects
on the number and performances of native centres in commercially available
samples. Although displaying significant variability in several photo physical
properties (emission wavelength, emission rate instabilities, saturation
behaviours), these centres generally display appealing photophysical properties
for applications as single photon sources: short lifetimes, high emission rates
and strongly polarized light. The native centres are tentatively attributed to
impurities incorporated in the diamond crystal during the CVD growth of
high-quality type IIa samples, and offer promising perspectives in
diamond-based photonics.Comment: 27 pages, 10 figures. Submitted to "New Journal of Phsyics",
NJP-100003.R
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