We study a (k,m)-threshold controlling scheme for controlled quantum teleportation. A usual polynomial coding over GF(p) with prime p > m − 1 needs to distribute a d-dimensional qudit with d ≥ p to each controller for this purpose. We propose a scheme using m qubits (twodimensional qudits) for the controllers’ portion, following a discussion on the benefit of a quantum control in comparison to ...

We review and compare Bell-state measurement and quantum teleportation schemes using linear optics with three different types of resources, i.e., two-photon pairs, entangled coherent states and hybrid entangled states. Remarkably, perfect teleportation with linear optics is possible in principle based on a hybrid approach that combines two-photon pairs and entangled coherent states. It turns ou...

We study the two qubits Heisenberg XX chain with magnetic impurity in the presence of the external magnetic field and calculate the optimal fidelity of standard teleportation via the thermal equilibrium state. It is found that the combined influence of magnetic impurity and external magnetic field can increase the critical temperatures of entanglement and quantum teleportation without limit. Th...

We point out that the mutual annihilation of an electron-hole pair at a tunnel barrier leads to teleportation of the state of the annihilated electron to a second, distant electron--if the latter was previously entangled with the annihilated hole. We propose an experiment, involving low-frequency noise measurements on a two-dimensional electron gas in a high magnetic field, to detect teleportat...

We study the effects of relativistic motion on quantum teleportation and propose a realizable experiment where our results can be tested. We compute bounds on the optimal fidelity of teleportation when one of the observers undergoes nonuniform motion for a finite time. The upper bound to the optimal fidelity is degraded due to the observer's motion. However, we discuss how this degradation can ...

We present a general method to construct fault-tolerant quantum logic gates with a simple primitive, which is an analog of quantum teleportation. The technique extends previous results based on traditional quantum teleportation @Gottesman and Chuang, Nature ~London! 402, 390 ~1999!# and leads to straightforward and systematic construction of many fault-tolerant encoded operations, including the...

In this letter we analyze the efficacy of the entangled output of Pati-Braunstein deletion machine [3] as a teleportation channel. We analyze the possibility of it violating the Bell’s inequality. Interestingly we find that for all values of α the state does not violate the Bell’s inequality but when used as a teleportation channel can give a fidelity higher than the classical optimum (i.e 2 3 ).

I n the past few years, significant improvements have been achieved in quantum communication. To extend the communication range, however, a new technology based on quantum memories needs to be developed. In PNAS, Bao et al. (1) give an example of the building blocks of the quantum communication networks we may expect to see in the future. These complex systems will be built on the basic ingredi...