Some Quantum States Prepared with Polynomial Quantum Circuit

The quantum state preparation involved in quantum information processing greatly depends on the quantum computer models. In this paper we give a novel scheme for some quantum states preparation without any decomposition of global quantum gates. Our circuit reduces the exponential CNOT gates to polynomial of qubit numbers, i.e., n(n?1)/2 without requirements of quantum register. And the depth is changed from the currently known exponential circuits to n blocks, or polynomial for its detailed implementation. This method is also useful for multi-level quantum systems and expected to help in designing and building large-scale quantum applications using present physical technologies.