scholarly journals MEASUREMENT IN CONTROL AND DISCRIMINATION OF ENTANGLED PAIRS UNDER SELF-DISTORTION

2011 ◽  
Vol 09 (supp01) ◽  
pp. 165-179
Author(s):  
FRANCISCO DELGADO
Keyword(s):  
Magnetic Field ◽  
Quantum Correlations ◽  
Inhomogeneous Magnetic Field ◽  
Original State ◽  
Communication Processes ◽  
Local Measurements ◽  
Non Local ◽  
And Behavior ◽  
And Control ◽  
Measurement And Control

Quantum correlations and entanglement are fundamental resources for quantum information and quantum communication processes. Developments in these fields normally assume stable resources, not susceptible of distortion. That is not always the case, Heisenberg interactions between qubits can produce distortion on entangled pairs generated for engineering purposes (e. g. quantum computation or quantum cryptography). The presence of parasite magnetic fields modifies the expected properties and behavior for which the pair was intended. Quantum measurement and control help to discriminate the original state in order to correct it or reconstruct it using some procedures which do not alter their quantum nature. Different kinds of quantum entangled pairs driven by a Heisenberg Hamiltonian with an additional inhomogeneous magnetic field become distorted. They can be reconstructed by adding an external magnetic field with fidelity close to one. In addition, each state can be efficiently discriminated. Combining both processes, first reconstruction without discrimination and after discrimination with adequate non-local measurements, it is possible to (a) improve the discrimination, and (b) reprepare faithfully the original state. The complete process gives fidelities better than 0.9. Some results about a class of equivalence for the required measurements are found, allowing to select the experimentally most adequate.

Measurement and Control of the Magnetic Field in a Beta Spectrometer

1964 ◽  
Vol 35 (8) ◽  
pp. 1072-1072 ◽  
Author(s):  
A. A. Bartlett ◽  
Howard Shafer ◽  
J. R. Keith
Keyword(s):  
Magnetic Field ◽  
Beta Spectrometer ◽  
And Control ◽  
Measurement And Control ◽  
The Magnetic Field

scholarly journals An artificial spiking quantum neuron

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lasse Bjørn Kristensen ◽  
Matthias Degroote ◽  
Peter Wittek ◽  
Alán Aspuru-Guzik ◽  
Nikolaj T. Zinner
Keyword(s):  
Time Series Prediction ◽  
Dynamical Evolution ◽  
Building Blocks ◽  
Quantum Correlations ◽  
Neuromorphic Hardware ◽  
Local Measurements ◽  
Non Local ◽  
Elementary Building ◽  
Learning Protocols

AbstractArtificial spiking neural networks have found applications in areas where the temporal nature of activation offers an advantage, such as time series prediction and signal processing. To improve their efficiency, spiking architectures often run on custom-designed neuromorphic hardware, but, despite their attractive properties, these implementations have been limited to digital systems. We describe an artificial quantum spiking neuron that relies on the dynamical evolution of two easy to implement Hamiltonians and subsequent local measurements. The architecture allows exploiting complex amplitudes and back-action from measurements to influence the input. This approach to learning protocols is advantageous in the case where the input and output of the system are both quantum states. We demonstrate this through the classification of Bell pairs which can be seen as a certification protocol. Stacking the introduced elementary building blocks into larger networks combines the spatiotemporal features of a spiking neural network with the non-local quantum correlations across the graph.

Research on the Measurement and Control Technology of Controllable Alternating Magnetic Field Generator to Magnetized Breed

2013 ◽  
Vol 303-306 ◽  
pp. 601-606
Author(s):  
Guo Wen Hu ◽  
Li Sheng Zhang ◽  
Lin Wang ◽  
Yin Jie Wang
Keyword(s):  
Magnetic Field ◽  
Control Method ◽  
Magnetic Energy ◽  
Voltage Regulation ◽  
Resonant Circuit ◽  
Magnetic Field Measurement ◽  
Control Technology ◽  
Magnetic Field Generation ◽  
And Control ◽  
Measurement And Control

Controlled and alternating induction magnetic field generation device which induces plant seeds to breed on floor space has been developed. The incentive ferrite induction coil is used in the device to produce induced magnetic field. The common AC-DC-AC topology was adopted for the variable frequency power supply, and AC power inverter circuit adopts SPWM inverter frequency modulation and voltage regulation mode, realizing the sinusoidal VVF. In order to improve the conversion efficiency of system electrical energy to magnetic energy, the RLC series resonant circuit is chosen in the circuit of output magnetic field. Measurement and control system using DSP microcomputer measurement and control technology and digital PID control method. The frequency and intensity of inductive magnetic field in the air gap changes as the changes of current intensity in coils. The experimental study of rice seeds shows that test result is obviously better than traditional biological magnetization induced breeding technique of fixed magnetic poles.

Geophysical Variables and Behavior: XI. Open-Field Behaviors in Young Rats Exposed to an ELF Rotating Magnetic Field

1983 ◽  
Vol 52 (2) ◽  
pp. 343-349 ◽  
Author(s):  
Klaus-Peter Ossenkopp ◽  
Margitta D. Ossenkopp
Keyword(s):  
Magnetic Field ◽  
Open Field ◽  
Rotating Magnetic Field ◽  
Male Rats ◽  
Albino Rats ◽  
Activity Levels ◽  
Experimental Conditions ◽  
Male And Female ◽  
And Behavior ◽  
And Control

Male and female albino rats 27 days of age were exposed to a 0.5-Hz rotating magnetic field (RMF) (2-30 gauss) for 21 days. Both experimental and control rats were tested in an open-field apparatus prior to imposition of experimental conditions, at 7, 15, and 21 days after the start of the experiment, and a final test occurred 3 days after the magnets were removed from the RMF apparatus. Male rats increased their activity levels and decreased their latency to ambulate in the open field, relative to control rats. The female experimental rats did not differ from controls on these measures. Both male and female RMF-exposed rats defecated less than control rats. Effects on latency and activity were still evident 3 days after removal of the magnets. These results indicate that exposure to a 0.5-Hz RMF makes rats less emotionally reactive to novel situations. It is suggested that these effects may be mediated by an effect of the RMF on the pineal gland.

scholarly journals Quantum memory and quantum correlations of Majorana qubits used for magnetometry

2020 ◽  
Vol 20 (11&12) ◽  
pp. 935-956
Author(s):  
H. Rangani ◽  
S. Haseli
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Quantum Correlations ◽  
Quantum Memory ◽  
Local Characteristic ◽  
Markovian Dynamics ◽  
Non Local ◽  
Majorana Modes ◽  
Local Nature

We address how the non-local nature of the topological qubits, realized by Majorana modes and driven by an external magnetic field, can be used to control the non-Markovian dynamics of the system. It is also demonstrated that the non-local characteristic plays a key role in control and protection of quantum correlations between Majorana qubits. Moreover, we discuss how those non-local qubits help us to enhance quantum magnetometry.

Sign in / Sign up

Export Citation Format

Share Document