scholarly journals Quantum State Transmission in a Superconducting Charge Qubit-Atom Hybrid

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Deshui Yu ◽  
María Martínez Valado ◽  
Christoph Hufnagel ◽  
Leong Chuan Kwek ◽  
Luigi Amico ◽  
...  
Keyword(s):  
Quantum State ◽  
High Speed ◽  
Rydberg Atom ◽  
Hybrid Structure ◽  
Spectroscopic Techniques ◽  
Charge Qubit ◽  
Superconducting Device ◽  
Long Time ◽  
State Transmission ◽  
Atomic States

Abstract Hybrids consisting of macroscopic superconducting circuits and microscopic components, such as atoms and spins, have the potential of transmitting an arbitrary state between different quantum species, leading to the prospective of high-speed operation and long-time storage of quantum information. Here we propose a novel hybrid structure, where a neutral-atom qubit directly interfaces with a superconducting charge qubit, to implement the qubit-state transmission. The highly-excited Rydberg atom located inside the gate capacitor strongly affects the behavior of Cooper pairs in the box while the atom in the ground state hardly interferes with the superconducting device. In addition, the DC Stark shift of the atomic states significantly depends on the charge-qubit states. By means of the standard spectroscopic techniques and sweeping the gate voltage bias, we show how to transfer an arbitrary quantum state from the superconducting device to the atom and vice versa.

scholarly journals Erratum: Corrigendum: Quantum State Transmission in a Superconducting Charge Qubit-Atom Hybrid

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Deshui Yu ◽  
María Martínez Valado ◽  
Christoph Hufnagel ◽  
Leong Chuan Kwek ◽  
Luigi Amico ◽  
...  
Keyword(s):  
Quantum State ◽  
Charge Qubit ◽  
State Transmission

scholarly journals Adaptive quantum state tomography with neural networks

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yihui Quek ◽  
Stanislav Fort ◽  
Hui Khoon Ng
Keyword(s):  
Machine Learning ◽  
Quantum State ◽  
The State ◽  
Learning To Learn ◽  
Seamless Integration ◽  
Quantum State Tomography ◽  
Flexible Machine ◽  
Meta Learning ◽  
Long Time ◽  
State Tomography

AbstractCurrent algorithms for quantum state tomography (QST) are costly both on the experimental front, requiring measurement of many copies of the state, and on the classical computational front, needing a long time to analyze the gathered data. Here, we introduce neural adaptive quantum state tomography (NAQT), a fast, flexible machine-learning-based algorithm for QST that adapts measurements and provides orders of magnitude faster processing while retaining state-of-the-art reconstruction accuracy. As in other adaptive QST schemes, measurement adaptation makes use of the information gathered from previous measured copies of the state to perform a targeted sensing of the next copy, maximizing the information gathered from that next copy. Our NAQT approach allows for a rapid and seamless integration of measurement adaptation and statistical inference, using a neural-network replacement of the standard Bayes’ update, to obtain the best estimate of the state. Our algorithm, which falls into the machine learning subfield of “meta-learning” (in effect “learning to learn” about quantum states), does not require any ansatz about the form of the state to be estimated. Despite this generality, it can be retrained within hours on a single laptop for a two-qubit situation, which suggests a feasible time-cost when extended to larger systems and potential speed-ups if provided with additional structure, such as a state ansatz.

scholarly journals Superconductor qubits hamiltonian approximations effect on quantum state evolution and control

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javad Sharifi
Keyword(s):  
Quantum State ◽  
Charge Qubit ◽  
Gate Operation ◽  
Goal State ◽  
Expected Time ◽  
State Evolution ◽  
Angle Of Deviation ◽  
Hadamard Gate ◽  
Phase Qubit ◽  
And Control

AbstractMicrowave IQ-mixer controllers are designed for the three approximated Hamiltonians of charge, phase and flux qubits and the controllers are exerted both on approximate and precise quantum system models. The controlled qubits are for the implementation of the two quantum-gates with these three fundamental types of qubits, Quantum NOT-gate and Hadamard-gate. In the charge-qubit, for implementation of both gates, in the approximated and precise model, we observed different controlled trajectories. But fortunately, applying the controller designed for the approximated system over the precise system leads to the passing of the quantum state from the desired state sooner that the expected time. Phase-qubit and flux qubit have similar behaviour under the control system action. In both of them, the implementation of NOT-gate operation led to same trajectories which arrive at final goal state at different times. But in both of those two qubits for implementation of Hadamard-gate, desired trajectory and precise trajectory have some angle of deviation, then by exerting the approximated design controller to precise system, it caused the quantum state to approach the goal state for Hadamard gate implementation, and since the quantum state does not completely reach the goal state, we can not obtain very high gate fidelity.

Quantum state transmission through a spin chain in finite-temperature heat baths

2021 ◽  
Vol 54 (15) ◽  
pp. 155303
Author(s):  
Zhao-Ming Wang ◽  
Feng-Hua Ren ◽  
Da-Wei Luo ◽  
Zhan-Yuan Yan ◽  
Lian-Ao Wu
Keyword(s):  
Quantum State ◽  
Finite Temperature ◽  
Spin Chain ◽  
Temperature Heat ◽  
State Transmission

scholarly journals Research on Bogie Frame Lateral Instability of High-Speed Railway Vehicle

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Chen Wang ◽  
Shihui Luo ◽  
Ziqiang Xu ◽  
Chang Gao ◽  
Weihua Ma
Keyword(s):  
High Speed ◽  
Dynamics Simulation ◽  
Lateral Acceleration ◽  
Railway Vehicle ◽  
Lateral Instability ◽  
Bogie Frame ◽  
High Speed Railway ◽  
Long Time ◽  
Line Test ◽  
Equivalent Conicity

In order to find out the reason for the bogie frame instability alarm in the high-speed railway vehicle, the influence of wheel tread profile of the unstable vehicle was investigated. By means of wheel-rail contact analysis and dynamics simulation, the effect of tread wear on the bogie frame lateral stability was studied. The result indicates that the concave wear of tread is gradually aggravated with the increase of operation mileage; meanwhile the wheel-rail equivalent conicity also increases. For the rail which has not been grinded for a long time, the wear of gauge corner and wide-worn zone is relatively severe; the matching equivalent conicity is 0.31-0.4 between the worn rail and the concave-worn-tread wheel set. The equivalent conicity between the grinded rail and the concave-worn tread is below 0.25; the equivalent conicities are always below 0.1 between the reprofiled wheel set and various rails. The result of the line test indicates that the lateral acceleration of bogie frame corresponding to the worn wheel-rail can reach 8.5m/s2, and the acceleration after the grinding is reduced below 4.5m/s2. By dynamics simulation, it turns out that the unreasonable wheel-rail matching relationship is the major cause of the bogie frame lateral alarm. With the tread-concave wear being aggravated, the equivalent conicity of wheel-rail matching constantly increases, which leads to the bogie frame lateral instability and then the frame instability alarm.

Induced Flow Reciprocating Pump Theory Supported by New Performance Data

1972 ◽  
Vol 94 (4) ◽  
pp. 706-714 ◽  
Author(s):  
J. D. Burton ◽  
J. Lobo-Guerrero U.
Keyword(s):  
High Speed ◽  
Performance Data ◽  
Experimental Measurements ◽  
Long Time ◽  
Induced Flow ◽  
Hydraulic Accumulator ◽  
Reciprocating Pump

Reciprocating pumps have been employed in conjunction with air vessels and fluid accumulators for a long time in order to reduce maximum cylinder pressures and energy wastage in friction. More recently, diaphragm pumps, run at high speed, have been built utilizing a hydraulic accumulator or capacitance in conjunction with a hydraulic inductance, in order to greatly increase the flow output. Volumetric efficiencies of over 250 percent have been obtained. The present paper describes briefly this induced flow principle and then compares theoretical solutions with experimental measurements taken in the first commercially available pump of this type.

scholarly journals High speed internet development in Africa using 4G-LTE technology-a review

2019 ◽  
Vol 8 (2) ◽  
pp. 577-585
Author(s):  
Mohamed Njikam ◽  
Nanna S. ◽  
Shahrin S. ◽  
Mohd Fairuz Iskandar Othman
Keyword(s):  
High Speed ◽  
Telecommunication Networks ◽  
African Continent ◽  
African Countries ◽  
Lte Networks ◽  
Telecommunication Infrastructure ◽  
Long Time ◽  
Populated Region ◽  
4G Lte ◽  
Internet Development

The African continent is ranked second most populated region and has a huge amount of natural resources to be locally transformed or outsourced overseas. The traditional telecommunications system has helped connect people and enabled them to manage their businesses and trading in Africa for a long-time; many African countries have embarked early in changing their network and technology systems during the first years of the information age. Over a few decades ago, the introduction of new telecommunication methods and techniques have influenced much of African countries’ growth via different perspectives. The situation has triggered an enormous interest in people. They analyzed the factors supporting such changes, which in the case of this paper is all about the advent and adoption of LTE/4G-LTE technologies including its service commercialization in Africa. This review article attempts to provide an overview of 4G-LTE networks technologies and the internet; it includes the current evolution of telecommunication networks within and even beyond the African continent, assisted by the 4G-LTE expansion. An extended view is provided throughout this article’s development with respect to what could be expected (or is missing) for the sake of this continent’s telecommunication infrastructure enhancement and a better QoS to Africa’s dwellers.

Catalytic Reduction Performance of Carboxylated Alginic Acid Derivatives

2021 ◽  
Author(s):  
Raed H. Althomali ◽  
Khalid A. Alamry ◽  
Mahmoud Hussein Abdo ◽  
Shams H. Abdel-Hafez
Keyword(s):  
Metal Complexes ◽  
Metal Ion ◽  
Alginic Acid ◽  
Catalytic Reduction ◽  
Organic Dyes ◽  
Reduction Process ◽  
Spectroscopic Techniques ◽  
Reduction Behavior ◽  
Long Time ◽  
Ft Ir

Abstract In this study, the catalytic reduction behavior of carboxylated alginic acid derivatives has been investigated against the harmful organic dyes including Methyl Orange (MO) and Congo Red (CR). Alginic acid was firstly oxidized through an easy addition of KMnO4 as an oxidizing agent. A carboxylated alginic acid (CAA) has been interacted with selected metal ions (Sn, Fe, Ni, and Zr) through coordination bonds at the value of pH = 4 to form the corresponding metal complexes namely: Sn-CAA, Fe-CAA, Ni-CAA and Zr-CAA. The consistency of the coordination was confirmed by several spectroscopic techniques including FT-IR, XRD, SEM, and EDX. The catalytic reduction of these metal ion-based products was carried out against MO and CR in the presence of NaBH4 as a reducing agent under UV irradiation. All catalysts based metal complexes showed enhanced catalytic reduction against CR compared to MO. Among all those mentioned metal complexes Sn-CAA showed the best catalytic reduction of these dyes. The time taken by the Sn-CAA for CR, and MO is 5 and 7min respectively. Ni-CAA was classified as the second efficient product against both dyes, where the reduction process took 20 and 9 min respectively. The other two catalysts took a long time for CR and MO reduction. Zr-CAA showed more than 80 % reduction of only CR dye within 20 min. Whereas, Fe-CAA did not show any significant sign of reduction against both the dyes after the same time. The order of higher catalytic reduction was illustrated as: Sn-CAA > Ni-CAA > Zr-CAA = Fe-CAA.

An Analysis of Heave Added Mass and Damping of a Surface-Effect Ship

1981 ◽  
Vol 25 (01) ◽  
pp. 44-61
Author(s):  
C. H. Kim ◽  
S. Tsakonas
Keyword(s):  
Free Surface ◽  
High Speed ◽  
Surface Effect ◽  
Practical Method ◽  
Added Mass ◽  
Damping Coefficients ◽  
Calm Water ◽  
Surface Effect Ship ◽  
Long Time ◽  
Computational Procedures

The analysis presents a practical method for evaluating the added-mass and damping coefficients of a heaving surface-effect ship in uniform translation. The theoretical added-mass and damping coefficients and the heave response show fair agreement with the corresponding experimental values. Comparisons of the coupled aero-hydrodynamic and uncoupled analytical results with the experimental data prove that the uncoupled theory, dominant for a long time, that neglects the free-surface effects is an oversimplified procedure. The analysis also provides means of estimating the wave elevation of the free surface, the escape area at the stern and the volume which are induced by a heaving surface-effect ship in uniform translation in otherwise calm water. Computational procedures have been programmed in the FORTRAN IV language and adapted to the PDP-10 high-speed digital computer.

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