45 research outputs found
Quantum Simulation of Open Quantum Systems Using Density-Matrix Purification
Electronic structure and transport in realistically-sized systems often
require an open quantum system (OQS) treatment, where the system is defined in
the context of an environment. As OQS evolution is non-unitary, implementation
on quantum computers -- limited to unitary operations -- is challenging. We
present a general framework for OQSs where the system's density
matrix is recast as a wavefunction which can be evolved by unitary
transformations. This theory has two significant advantages over conventional
approaches: (i) the wavefunction requires only an -qubit, compared to
-qubit, bath for an -qubit system and (ii) the purification includes
dynamics of any pure-state universe. We demonstrate this method on a two-level
system in a zero temperature amplitude damping channel and a two-site quantum
Ising model. Quantum simulation and experimental-device results agree with
classical calculations, showing promise in simulating non-unitary operations on
NISQ quantum devices
Intraocular lenses in age-related macular degeneration
Purpose:
The aim of this work is to review the lenses, assessing their advantages and disadvantages. We describe a total of seven types of intraocular lenses (IOLs) recommended for age-related macular degeneration (AMD).
Methods:
We used the PubMed web platform to search for implantable devices in various stages of AMD. We searched for both prospective and retrospective studies and also case reports.
Results:
Clinical results in AMD patients have been described for a total of seven types of IOLs recommended for AMD: an implantable miniature telescope (IMT), IOL-VIP System, Lipshitz macular implant (LMI), sulcus-implanted Lipshitz macular implant, LMI-SI, Fresnel Prism Intraocular Lens, iolAMD and Scharioth Macula Lens.
Conclusions:
We conclude that to objectively ascertain the effectiveness and safety of these lenses, further independent clinical studies with longer follow-up data are necessary prior to the general use of these optical devices