Quantum computation in triangular decoherence-free subdynamic space

Abstract

A formalism of quantum computing with 2000 qubits or more in decoherence-free subspaces is presented. The subspace is triangular with respect to the index related to the environment. The quantum states in the subspaces are projected states ruled by a subdynamic kinetic equation. These projected states can be used to perform general, large-scale decoherence-free quantum computing.

Efficient Concentration Protocols for the Single-Photon Entanglement State with Polarization Feature

“…If a suitable VBS2 with t ′′ 1 = |α| 2 can be provided, | − 2 a1b9 in Equation (32) can be ultimately converted to the state in Equation (18). Until now, the concentration process for Equation (5) is completed, and its success probability is:…”

“…Entanglement is central to almost all the protocols of practical quantum communication and computation tasks, such as the quantum cryptography [1], quantum teleportation [2][3][4][5], quantum secure direct communication [6][7][8], quantum repeaters [9,10], quantum dense coding [11], entanglement-based quantum key distribution [12][13][14], and some other quantum communication applications [15][16][17][18][19]. During the past decade, a large number of single-particle and multi-particle entanglement states have been successfully generated [20][21][22][23].…”

Decoherence in quantum cavities: Environmental erasure of carpet-type structures

“…Decoherence is ubiquitous in a myriad of systems and applications [9], e.g., quantum dots [10][11][12], quantum game theory [13,14], quantum walks [15,16], quantum information [17][18][19][20], two-level systems [21][22][23], cavities [24][25][26], ion trapping [27] or the spin-boson model [9,28]. Similarly different models have been proposed to study and quantify its effects on the coherence of quantum systems as well as to control them [29][30][31][32][33][34][35][36][37][38][39]. Furthermore, a number of experiments has also been conduced in recent year to test some of such models at a fundamental level [40][41][42][43].…”