arXiv subjects

Jin-Yuan Hsieh

Publications and source records attributed to Jin-Yuan Hsieh.

10 recordsLinked to original sources

arXiv2005

Analytical technique for simplification of the encoder-decoder circuit for a perfect five-qubit error correction

Simpler encoding and decoding networks are necessary for more reliable quantum error correcting codes (QECCs). The simplification of the encoder-decoder circuit for a perfect five-qubit QECC can be derived analytically if the QECC is converted from its equivalent one-way entanglement purification protocol (1-EPP). In this work, the analytical method to simplify the encoder-decoder circuit is introduced and a circuit that is as simple as the existent simplest circuits is presented as an example. The encoder-decoder circuit presented here involves nine single- and two-qubit unitary operations, only six of which are controlled-NOT (CNOT) gates.

quant-ph↗

arXiv2005

Effect of cavity photons on the generation of multi-particle entanglement

A study on the cause of the multi-particle entanglement is presented in this work. We investigate how dot-like single quantum well excitons, which are independently coupled through a single microcavity mode, evolve into maximally entangled state as a series of conditional measurements are taken on the cavity field state. We first show how cavity photon affects the entanglement purity of the double-exciton Bell state and the triple-exciton W state. Generalization to multi-excitons W states is then derived analytically. Our results pave the way for studying the crucial cause of multi-particle collective effect.

quant-ph↗

arXiv2004

An improved phase error tolerance in Quantum search algorithm

As the matching condition in Grover search algorithm is transgressed due to inevitable errors in phase inversions, it gives a reduction in maximum probability of success. With a given degree of maximum success, we have derive the generalized and imroved criterion for tolerated error and corresponding size of quantum database under the inevitable gate imperfections. The vanished inaccurancy to this condition has also been shown. Besides, a concise formula for evaluating minimum number of iterations is also presented in this work.

quant-ph↗

arXiv2004

Creating Boolean Functions for the Five-EPR-Pair, Single-Error-Correcting Code

A quantum single-error-correcting scheme can be derived from a one-way entanglement purification protocol in purifying one Bell state from a finite block of five Bell states. The main issue to be concerned with in the theory of such an error-correction is to create specific linear Boolean functions that can transform the sixteen error syndromes occurring in the error-correcting code onto their mappings so that one Bell state is corrected whenever the other four in the finite block are measured. The Boolean function is performed under the effect of its associated sequence of basic quantum unilateral and bilateral operations. Previously, the Boolean function is created in use of the Monte Carlo computer search method. We introduce here a systematic scenario for creating the Boolean function and its associated sequence of operations so that we can do the job in an analytical way without any trial and error effort. Consequently, all possible Boolean functions can in principle be created by using our method. Furthermore, for a deduced Boolean function, we can also in the spirit of our method derive its best associated sequence of operations which may contain the least number of total operations or the least number of the bilateral XOR operations alone. Some results obtained in this work show the capability of our method in creating the Boolean function and its sequence of operations.

quant-ph↗

arXiv2004

A simplification of entanglement purification

An idea of hybrid maps is proposed to establish standard entanglement purification protocols which guarantee to purify any distillable state to a desired maximally entangled pure state all by the standard purification local operations and classical communications. The protocols proposed in this work, in which two state transformations are used, perform better than the IBM and Oxford protocols in the sense that they require fewer operation times in yielding a same amount of the desired pure state. One of the proposed protocol in this work can even lead to a higher improved output yield when it is combined with the hashing protocol, as compared with the combined algorithm consisting of the Oxford and the hashing protocol.

quant-ph↗

arXiv2002

Formulation of a Family of Sure-Success Quantum Search Algorithms

In this work, we consider a family of sure-success quantum algorithms, which is grouped into even and odd members for solving a generalized Grover search problem. We prove the matching conditions for both groups and give the corresponding formulae for evaluating the iterations or oracle calls required in the search computation. We also present how to adjust the phase angles in the generalized Grover operator to ensure the sure-success if minimal oracle calls are demanded in the search.

quant-ph↗

arXiv2002

Hamiltonian and measuring time for analog quantum search

We derive in this study a Hamiltonian to solve with certainty the analog quantum search problem analogue to the Grover algorithm. The general form of the initial state is considered. Since the evaluation of the measuring time for finding the marked state by probability of unity is crucially important in the problem, especially when the Bohr frequency is high, we then give the exact formula as a function of all given parameters for the measuring time.

quant-ph↗

arXiv2002

Multi-object searching algorithm using subgrouped oracles

We present in this work, if a set of well organized suboracles is available, an algorithm for multiobject search with certainty in an unsorted database of $N$ items. Depending on the number of the objects, the technique of phase tunning is included in the algorithm. If one single object is to be searched, this algorithm performs a factor of two improvement over the best algorithm for a classical sorted database. While if the number of the objects is larger than one, the algorithm requires slightly less than $\log_{4}N$ queries, but no classical counterpart exists since the resulting state is a superposition of the marked states.

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arXiv2001

A General Phase Matching Condition for Quantum Searching Algorithm

A general consideration on the phase rotations in quantum searching algorithm is taken in this work. As four phase rotations on the initial state, the marked states, and the states orthogonal to them are taken account, we deduce a phase matching condition for a successful search. The optimal options for these phase are obtained consequently.

quant-ph↗

arXiv2001

A General SU(2) Formulation for Quantum Searching with Certainty

A general quantum search algorithm with arbitrary unitary transformations and an arbitrary initial state is considered in this work. To serach a marked state with certainty, we have derived, using an SU(2) representation: (1) the matching condition relating the phase rotations in the algorithm, (2) a concise formula for evaluating the required number of iterations for the search, and (3) the final state after the search, with a phase angle in its amplitude of unity modulus. Moreover, the optimal choices and modifications of the phase angles in the Grover kernel is also studied.

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