Related papers: Decoherence Control for Optical Qubits
We present a scheme able to protect the quantum states of a cavity mode against the decohering effects of photon loss. The scheme preserves quantum states with a definite parity, and improves previous proposals for decoherence control in…
In the lectures we will be concerned with some aspects of physical implementations of quantum gate operations which are necessary for quantum information processing. We will discuss two possible realizations. One of them is based on qubits…
We employ optimal control theory to design optimized quantum gates for solid-state qubits subject to decoherence. At the example of a gate-controlled semiconductor quantum dot molecule we demonstrate that decoherence due to phonon couplings…
Accurately controlling the quantum coherence of photons is pivotal for their applications in quantum sensing and quantum imaging. Here, we propose the utilization of quantum entanglement and local phase manipulation techniques to control…
This paper discusses work developed in recent years, in the domain of quantum optics, which has led to a better understanding of the classical limit of quantum mechanics. New techniques have been proposed, and experimentally demonstrated,…
Decoherence is usually deemed detrimental to quantum information processing. Its control and minimization require significant costs and operating overheads, constituting a major hurdle to commercialize quantum technology. Yet, quantum…
We present a protocol to construct an arbitrary quantum circuit. The quantum bits (qubits) are encoded in polarisation states of single photons. They are stored in spatially separated dense media deposed in an optical cavity. Specific…
Decoherence may significantly affect the polarization state of optical pulses propagating in dispersive media because of the unavoidable presence of more than a single frequency in the envelope of the pulse. Here we report on the…
Quantum computers require technologies that offer both sufficient control over coherent quantum phenomena and minimal spurious interactions with the environment. We show, that photons confined to photonic crystals, and in particular to…
Decoherence-free states protect quantum information from collective noise, the predominant cause of decoherence in current implementations of quantum communication and computation. Here we demonstrate that spontaneous parametric…
We consider the possibility to measure the quantum decoherence using gravitational wave interferometers. Gravitational wave interferometers create the superposition state of photons and measure the interference of the photon state. If the…
We propose a new scheme for solid-state photonic quantum computation in which trapped photons in optical cavities are taken as a quantum bit. Quantum gates can be realized by coupling the cavities with quantum dots through waveguides. The…
The cause of decoherence in a quantum system can be traced back to the interaction with the environment. As it has been pointed out first by Dicke, in a system of N two-level atoms where each of the atoms is individually dipole coupled to…
Coherent interaction of a quantum system with environment usually induces quantum decoherence. However, remarkably, in certain configurations the coherent system-environment coupling can be simultaneously explored to engineer a specific…
We study the physical implementation of the Photon Carnot engine (PCE) based on the cavity QED system [M. Scully et al, Science, \textbf{299}, 862 (2003)]. Here, we analyze two decoherence mechanisms for the more practical systems of PCE,…
We present novel models of quantum gates based on coupled quantum dots in which a qubit is regarded as the superposition of ground states in each dot. Coherent control on the qubit is performed by both a frequency and a polarization of a…
Several mechanisms that affect one and two photon coherence in optical fibers and their remedies are discussed. The results are illustrated on quantum cryptography experiments and on long distance Bell inequality tests.
Decoherence-free subspaces allow for the preparation of coherent and entangled qubits for quantum computing. Decoherence can be dramatically reduced, yet dissipation is an integral part of the scheme in generating stable qubits and…
To resist decoherence from destroying the phase factor of qubit state, it is important to use decoherence-free states for processing, transmitting and storing quantum information in quantum computing and quantum communication. We propose a…
One of the biggest challenges for implementing quantum devices is the requirement to perform accurate quantum gates. The destructive effects of interactions with the environment present some of the most difficult obstacles that must be…