Quantum conical designs

Quantum Designs

Quantum Fluctuations of Scalar Field in Conical Space

We consider vacuum polarization effect of a conformally coupled massless scalar field in the background produced by an idealized straight cosmic string. Using previous criterion we show the calculation of back reaction of the field to the metric in the context of semiclassical gravity theory is not valid in some regions due to large quantum fluctuations in the conical space. 03.70.+k, 05.40.+j,...

Normal forms for conical intersections in quantum chemistry

In quantum chemistry, the dynamics of heavy molecules is described by Schrödinger equations with energy level crossings. These crossings generate energy transfers at leading order between the modes as was earlier noticed by Landau and Zener in the 30’s. The mathematical analysis of these transfers relies on the use of normal forms. Here, we analyze the implications of Y. Colin de Verdière’s rec...

Quantum Circuit Designs for Gate-Model Quantum Computer Architectures

The power of quantum computers makes it possible to solve difficult problems more efficiently than is possible with traditional computers. Gate-model quantum computers provide an experimentally implementable architecture for quantum circuit computations. Here, we demonstrate an automated method for designing quantum circuits for experimental gate-model quantum computers. We define the Quantum T...

Quantum Compressed Sensing Using 2-Designs

We develop a method for quantum process tomography that combines the efficiency of compressed sensing with the robustness of randomized benchmarking. Our method is robust to state preparation and measurement errors, and it achieves a quadratic speedup over conventional tomography when the unknown process is a generic unitary evolution. Our method is based on PhaseLift, a convex programming tech...