Zhongguo kexue. Wulixue Lixue Tianwenxue
A new method for constructing entangled states via orthogonal arrays
Xiaoyuan Yu, Zha Xin-wei, CHE JunLing
Abstract
A pure quantum state of $N$ subsystems with $d$ levels each is called $k$-multipartite maximally entangled state, which we call a $k$-uniform state, if all its reductions to $k$ qubits are maximally mixed. Recently, Goyeneche and Zyczkowski proposed a method of constructing $k$-uniform states via orthogonal arrays, by which, we will also propose a new method to construct quantum states with orthogonal arrays in this paper, which is the method of increasing phase parameters. We can find the quantum states constructed via our new method by using the same orthogonal array, for four-qubit quantum states, not only are they 1-uniform states, also may become maximally entangled states; for five-qubit quantum states, we find that it can make the original 1-uniform states into 2-uniform states. In particular, for four-qubit quantum states, we can construct a series of new forms of maximally entangled states via our new method.