Is the Measurement Based Quantum Computing Search Algorithm Really Grovers Algorithm?

We question whether the measurement based quantum computing algorithm is in fact Grovers algorithm or simply a similar oracular search method. The two algorithms share several qualitative features especially in the case of the trivial 4 element search, which is the largest size photonic search algorithm that has been experimentally implemented to date. This has led some to refer to both substantiations as Grovers algorithm. We compare multiple features of the two algorithms including the behavior of the oracle tags and the entanglement dynamics, both qualitatively and quantitatively. We find significant and fundamental differences in the operation of the two algorithms, particularly in cases involving searches on more than four elements.

The Measurement Based Quantum Computing Search Algorithm is Faster than Grovers Algorithm

We find that the Measurement Based Quantum Computing (MBQC) search algorithm on an unsorted list is not the same as Grovers search algorithm (GSA).

A Multi-Layer Three Dimensional Superconducting Nanowire Photon Detector

Here we propose a new design paradigm for a superconducting nanowire single photon detector that uses a multi-layer architecture that places the electric leads beneath the nanowires. This allows for a very large number of detector elements, which we will call pixels in analogy to a conventional CCD camera, to be placed in close proximity. This leads to significantly better photon number resolution than current single and multi-nanowire meanders, while maintaining similar detection areas. We discuss the reset time of the pixels and how the design can be modified to avoid the latching failure seen in extremely short superconducting nanowires. These advantages give a multi-layer superconducting number-resolving photon detector significant advantages over the current design paradigm of long superconducting nanowire meanders. Such advantages are desirable in a wide array of photonics applications.

Proposed Experiment in Two-Qubit Linear Optical Photonic Gates for Maximal Success Rates

Here we propose an experiment in Linear Optical Quantum Computing (LOQC) using the framework first developed by Knill, Laflamme, and Milburn. This experiment will test the ideas of the authors previous work on imperfect LOQC gates using number-resolving photon detectors. We suggest a relatively simple physical apparatus capable of producing CZ gates with controllable fidelity less than 1 and success rates higher than the current theoretical maximum (S=2/27) for perfect fidelity. These experimental setups are within the reach of many experimental groups and would provide an interesting experiment in photonic quantum computing.