Modelling quantum register disentanglement

2018 ◽  
Vol 0 (7/2018) ◽  
pp. 31-43 ◽  
Author(s):  
Paweł, Aleksander Ryszawa
Keyword(s):  
Quantum State ◽  
Trade Off ◽  
Quantum Register ◽  
Operational Memory

Implementing quantum-inspired algorithms on classical computers suffers trade-off between the necessity of saving operational memory and the amount of memory necessary to fully represent a quantum state with possible entanglement. The latter is well known to consume the memory exponentially in the number of qubits. This paper sketches out the idea on how to reduce significantly the amount of necessary memory while distorting the entanglement moderately or not at all. At present, considered are real nonnegative probability amplitudes.

EFFICIENT ALGORITHM FOR INITIALIZING AMPLITUDE DISTRIBUTION OF A QUANTUM REGISTER

2001 ◽  
Vol 15 (27) ◽  
pp. 1259-1264 ◽  
Author(s):  
M. ANDRECUT ◽  
M. K. ALI
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Computation ◽  
Quantum State ◽  
Efficient Algorithm ◽  
Quantum Information Processing ◽  
Amplitude Distribution ◽  
Quantum Register

The preparation of a quantum register in an arbitrary superposed quantum state is an important operation for quantum computation and quantum information processing. Here, we present an efficient algorithm which requires a polynomial number of elementary operations for initializing the amplitude distribution of a quantum register.

scholarly journals Optimal universal quantum cloning: asymmetries and fidelity measures

2016 ◽  
Vol 16 (11&12) ◽  
pp. 991-1028
Author(s):  
Alastair Kay
Keyword(s):  
Quantum State ◽  
Quantum Cloning ◽  
Substantial Evidence ◽  
Quadratic Constraints ◽  
Trade Off ◽  
Unknown Quantum State ◽  
Universal Quantum ◽  
Fidelity Measures ◽  
Parameter Ranges ◽  
Universal Cloning

We study the problem of universal quantum cloning – taking several identical copies of a pure but unknown quantum state and producing further copies. While it is well known that it is impossible to perfectly reproduce the state, how well the copies can be cloned can be quantified using the fidelity. We examine how individual fidelities can be traded against each other, and how different fidelity measures can be incorporated. The broadly applicable formalism into which we transform the cloning problem is described as a series of quadratic constraints which are amenable to mathematical and computational scrutiny. As such, we reproduce all known results on optimal universal cloning, and push the recent results on asymmetric cloning much further, giving new trade-off relations between fidelities for broad classes of optimal cloning machines. We also provide substantial evidence that motivates why other parameter ranges (number of input copies) have not, and will not, yield to similar analysis.

A Flow-Preserving Algorithm for the Time-Cost Trade-Off Problem

1982 ◽  
Vol 14 (2) ◽  
pp. 109-113 ◽  
Author(s):  
Suleyman Tufekci
Keyword(s):  
Time Cost ◽  
Trade Off

Dual Goals for Speed and Accuracy on the Same Performance Task

2012 ◽  
Vol 11 (3) ◽  
pp. 118-126 ◽  
Author(s):  
Olive Emil Wetter ◽  
Jürgen Wegge ◽  
Klaus Jonas ◽  
Klaus-Helmut Schmidt
Keyword(s):  
Memory Scanning ◽  
Performance Task ◽  
Performance Tasks ◽  
Trade Off ◽  
Test Experiment ◽  
Trade Offs ◽  
New Finding ◽  
Sternberg Paradigm ◽  
Speed Accuracy ◽  
Speed And Accuracy

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.

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