Quantum algebra in the mixed light pseudoscalar meson states

In this paper, we investigate the entanglement degrees of pseudoscalar meson states via quantum algebra Y(su(3)). By making use of transition effect of generators J of Y(su(3)), we construct various transition operators in terms of J of Y(su(3)), and act them on eta-pion-eta mixing meson state. The entanglement degrees of both the initial state and final state are calculated with the help of entropy theory. The diagrams of entanglement degrees are presented. Our result shows that a state with desired entanglement degree can be achieved by acting proper chosen transition operator on an initial state. This sheds new light on the connect among quantum information, particle physics and Yangian algebra.Comment: 9 pages, 3 figure

DiCarloLab-Delft/PycQED_py3: Initial public release

Python3 version of PycQED using QCodes as backen

Efficient linear optical quantum computation

We consider realizing the efficient linear optical quantum computing scheme of Knill, Laflamme and Milburn [Nature 409, 46 (2001)]. A number of the issues in implementing a coincidence-basis version of a CNOT gate are addressed experimentally, including source brightness and mode quality

On-chip quantum teleportation

Integrated quantum optics provides great promise for enabling photonic experiments to reach new regimes of complexity. Chip-based fabrication enables sophisticated networks involving multiple interfering pathways in a compact and stable physical architecture. In a recent work [1] we demonstrated an advance in the complexity of these integrated devices by showing the first quantum interference of three separate input photons. Such complexity allows the demonstration of three qubit protocols never before realised on-chip. Here, we report the first results showing quantum teleportation on an integrated photonic circuit. Quantum teleportation provides the mechanism for quantum relay schemes and is an important constituent in linear optical quantum computing. Whilst demonstrations to date have relied upon complex and fragile bulk optical systems, being able to teleport quantum states on a compact and stable integrated architecture will be a critical step towards scalable realisations of these schemes

Integrated optical platform for photon-number resolving telecom-band detectors for photonic information processing

We report the development of the optical substrates for the demonstration of an integrated photon-number-resolving detector, operating in the telecom band at 1550 nm, employing an evanescently coupled design that allows it to be placed at arbitrary locations within a planar circuit. Up to five photons are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The detection efficiency is 7.2 ± 0.5%. The polarization sensitivity of the detector is also demonstrated

Reducing intrinsic loss in superconducting resonators by surface treatment and deep etching of silicon substrates

We present microwave-frequency NbTiN resonators on silicon, systematically achieving internal quality factors above 1?M in the quantum regime. We use two techniques to reduce losses associated with two-level systems: an additional substrate surface treatment prior to NbTiN deposition to optimize the metal-substrate interface and deep reactive-ion etching of the substrate to displace the substrate-vacuum interfaces away from high electric fields. The temperature and power dependence of resonator behavior indicate that two-level systems still contribute significantly to energy dissipation, suggesting that more interface optimization could further improve performance.QN/Quantum NanoscienceApplied Science

Entangling the motion of diamonds at room temperature

2012 Conference on Lasers and Electro-Optics, CLEO 2012

Entangling macroscopic diamonds at room temperature

10.1126/science.1211914Science33460601253-1256SCIE