Search results for "Circuit quantum electrodynamics"
showing 5 items of 5 documents
Quantum simulation of the spin-boson model with a microwave circuit
2017
We consider superconducting circuits for the purpose of simulating the spin-boson model. The spin-boson model consists of a single two-level system coupled to bosonic modes. In most cases, the model is considered in a limit where the bosonic modes are sufficiently dense to form a continuous spectral bath. A very well known case is the ohmic bath, where the density of states grows linearly with the frequency. In the limit of weak coupling or large temperature, this problem can be solved numerically. If the coupling is strong, the bosonic modes can become sufficiently excited to make a classical simulation impossible. Here, we discuss how a quantum simulation of this problem can be performed …
Accelerated stabilization of coherent photon states
2018
| openaire: EC/H2020/681311/EU//QUESS Control and utilization of coherent states of microwave photons is a ubiquitous requirement for the present and near-future implementations of solid-state quantum computers. The rate at which the photon state responds to external driving is limited by the relaxation rate of the storage resonator, which poses a trade-off between fast control and long storage time. Here, we present a control scheme that is designed to drive an unknown photon state to a desired coherent state much faster than the resonator decay rate. Our method utilizes a tunable environment which acts on an ancillary qubit coupled to the resonator. By periodically resetting the qubit and…
Microwave nanobolometer based on proximity Josephson junctions
2014
We introduce a microwave bolometer aimed at high-quantum-efficiency detection of wave packet energy within the framework of circuit quantum electrodynamics, the ultimate goal being single microwave photon detection. We measure the differential thermal conductance between the detector and its heat bath, obtaining values as low as $5\phantom{\rule{4.pt}{0ex}}\text{fW}/\mathrm{K}$ at $50\phantom{\rule{4.pt}{0ex}}\text{mK}$. This is one tenth of the thermal conductance quantum and corresponds to a theoretical lower bound on noise-equivalent power of order ${10}^{\ensuremath{-}20}\phantom{\rule{4.pt}{0ex}}\text{W}/\sqrt{\text{Hz}}$ at $50\phantom{\rule{4.pt}{0ex}}\text{mK}$. By measuring the dif…
Single and two-qubit dynamics in circuit QED architectures
2008
In this paper we overview our researches on the generation and the control of entangled states in the framework of circuit quantum electrodynamics. Applications in the context of quantum computing and quantum information theory are discussed.
Cavity-based architecture to preserve quantum coherence and entanglement
2015
Quantum technology relies on the utilization of resources, like quantum coherence and entanglement, which allow quantum information and computation processing. This achievement is however jeopardized by the detrimental effects of the environment surrounding any quantum system, so that finding strategies to protect quantum resources is essential. Non-Markovian and structured environments are useful tools to this aim. Here we show how a simple environmental architecture made of two coupled lossy cavities enables a switch between Markovian and non-Markovian regimes for the dynamics of a qubit embedded in one of the cavity. Furthermore, qubit coherence can be indefinitely preserved if the cavit…