Efficient Scheme for One-Way Quantum Computing in Thermal Cavities

Abstract

We propose a practical scheme for one-way quantum computing based on efficient generation of 2D cluster state in thermal cavities. We achieve a controlled-phase gate that is neither sensitive to cavity decay nor to thermal field by adding a strong classical field to the two-level atoms. We show that a 2D cluster state can be generated directly by making every two atoms collide in an array of cavities, with numerically calculated parameters and appropriate operation sequence that can be easily achieved in practical Cavity QED experiments. Based on a generated cluster state in Box (4) configuration, we then implement Grover's search algorithm for four database elements in a very simple way as an example of one-way quantum computing.Keywords Cluster state · Quantum computation · Cavity QED Over the past few years, the construction of a practical quantum computer has become a challenging goal for experimentalists. It is well known that the building blocks of a general quantum computer are single-qubit rotations and two-qubit quantum gates [1]. Recently, Briegel and Raussendorf [2,3] proposed a new idea for constructing quantum computer, known as one-way quantum computing, which shows that preparation of a particular entangled state, called cluster state, accompanied with local single qubit measurements, is sufficient for simulating any arbitrary quantum logic operations. Cluster state as a universal resource for general quantum computing has drawn extensive research interests [4][5][6][7][8]. Moreover, one way quantum computing by optical elements based on four-qubit cluster states was recently demonstrated experimentally [9]. It is hoped that experimental difficulties in performing complex quantum gates may be overcome by one-way quantum computing based on the generation of cluster state.

Perda de coerência e teletransporte em eletrodinâmica quântica de cavidades

“…A implementação física de tais estados é então de grande importância e vários sistemas físicos diferentes têm sido considerados com esse propósito. Mencionamos propostas envolvendo fótons [106][107][108][109][110], íons aprisionados [111][112][113], Eletrodinâmica Quântica de Cavidades (CQED) [114][115][116][117][118][119][120][121][122][123], sistemas híbridos envolvendo CQED e elementos de óptica linear [124,125], e circuitos quânticos supercondutores [126][127][128], dentre muitos outros.…”