Related papers: Quantum Phase Gate Operation Based on Nonlinear Op…
Optical networks implementing single-qudit quantum computation gates may exhibit superior properties to those for qubits as each of the optical elements in the network can work in parallel on many optical modes simultaneously. We present an…
Ideally, strong non-linearities could be used to implement quantum gates for photonic qubits by well controlled two photon interactions. However, the dependence of the non-linear interaction on frequency and time makes it difficult to…
The many-body state of carriers confined in a quantum dot is controlled by the balance between their kinetic energy and their Coulomb correlation. In coupled quantum dots, both can be tuned by varying the inter-dot tunneling and…
We study the quantum phase transition of a N two-level atomic ensemble interacting with an optical degenerate parametric process, which can be described by the finite size Dicke Hamiltonian plus counter-rotating and quadratic field terms.…
We discuss and implement experimentally a method for characterizing quantum gates operating on superpositions of coherent states. The peculiarity of this encoding of qubits is to work with a non-orthogonal basis, and therefore some…
For circuit-based quantum computation, experimental implementation of universal set of quantum logic gates with high-fidelity and strong robustness is essential and central. Quantum gates induced by geometric phases, which depend only on…
This thesis focuses on quantum information processing using the superconducting device, especially, on realizing quantum gates and algorithms in open quantum systems. Such a device is constructed by transmon-type superconducting qubits…
We propose a fast, scalable all-optical design for arbitrary two-qubit operations for defect qubits in diamond (NV centers) and in silicon carbide, which are promising candidates for room temperature quantum computing. The interaction…
We experimentally characterize a quantum photonic gate that is capable of converting multiqubit entangled states while acting only on two qubits. It is an important tool in large quantum networks, where it can be used for re-wiring of…
Quantum computers promise dramatic speed ups for many computational tasks. For large-scale quantum computation however, the inevitable coupling of physical qubits to the noisy environment imposes a major challenge for a real-life…
We show that a beam splitter of reflectivity one-third can be used to realize a quantum phase gate operation if only the outputs conserving the number of photons on each side are post-selected.
We examine a generic three state mechanism which realizes all fundamental single and double qubit quantum logic gates operating under the effect of adiabatically controllable static (radiation free) bias couplings between the states. At the…
We consider a network whose nodes are electromagnetic cavities, each coupled to a single three-level atom. The nodes are connected by optical fibers. Each atom is addressed by a control laser, which along with the cavity field drives atomic…
We propose a two-qubit collisional phase gate that can be implemented with available atom chip technology, and present a detailed theoretical analysis of its performance. The gate is based on earlier phase gate schemes, but uses a qubit…
Quantum electrodynamics of excitons in a cavity is shown to be relevant to quantum operations. We present a theory of an integrable solid-state quantum controlled-phase gate for generating entanglement of two photons using a coupled…
We study a two-level system (atom, superconducting qubit or quantum dot) strongly coupled to the single photonic mode of a cavity, in the presence of incoherent pumping and including detuning and dephasing. This system displays a striking…
We propose a geometric phase gate of two ion qubits that are encoded in two levels linked by an optical dipole-forbidden transition. Compared to hyperfine geometric phase gates mediated by electric dipole transitions, the gate has many…
Quantum computation with photons requires efficient two photon gates. We put forward a two photon entangling gate which uses an intermediate atomic system. The system includes a single Rydberg atom which can switch on and off photon…
The coherent evolution of two atomic qubits mediated by a set of bosonic field modes is investigated. By assuming a specific encoding of the quantum states in the internal levels of the two atoms we show that entangling quantum gates can be…
The quantum computing paradigm in photonics currently relies on the multi-port interference in linear optical devices, which is intrinsically based on probabilistic measurements outcome and thus non-deterministic. Devising a fully…