1,586 research outputs found
Efficient many-party controlled teleportation of multi-qubit quantum information via entanglement
We present a way to teleport multi-qubit quantum information from a sender to
a distant receiver via the control of many agents in a network. We show that
the original state of each qubit can be restored by the receiver as long as all
the agents collaborate. However, even if one agent does not cooperate, the
receiver can not fully recover the original state of each qubit. The method
operates essentially through entangling quantum information during
teleportation, in such a way that the required auxiliary qubit resources, local
operation, and classical communication are considerably reduced for the present
purpose
Efficient many-party controlled teleportation of multiqubit quantum information via entanglement
This is the published version, also available here: http://dx.doi.org/10.1103/PhysRevA.70.022329.We present a way to teleport multiqubit quantum information from a sender to a distant receiver via the control of many agents in a network. We show that the original state of each qubit can be restored by the receiver as long as all the agents collaborate. However, even if one agent does not cooperate, the receiver cannot fully recover the original state of each qubit. The method operates essentially through entangling quantum information during teleportation, in such a way that the required auxiliary qubit resources, local operation, and classical communication are considerably reduced for the present purpose
Error-prevention scheme with two pairs of qubits
This is the published version, also available here: http://dx.doi.org/10.1103/PhysRevA.66.034301.A scheme is presented for protecting one-qubit quantum information against decoherence due to a general environment and local exchange interactions. The scheme operates essentially by distributing information over two pairs of qubits and through error-prevention procedures. In the scheme, quantum information is encoded through a decoherence-free subspace for collective phase errors and exchange errors affecting the qubits in pairs; leakage out of the encoding space due to amplitude damping is reduced by quantum Zeno effect. In addition, how to construct decoherence-free states for n-qubit information against phase and exchange errors is discussed
Possible realization of entanglement, logical gates, and quantum-information transfer with superconducting-quantum-interference-device qubits in cavity QED
This is the published version, also available here: http://dx.doi.org/10.1103/PhysRevA.67.042311.We present a scheme to achieve maximally entangled states, controlled phase-shift gate, and SWAP gate for two superconducting-quantum-interference-device (SQUID) qubits, by placing SQUIDs in a microwave cavity. We also show how to transfer quantum information from one SQUID qubit to another. In this scheme, no transfer of quantum information between the SQUIDs and the cavity is required, the cavity field is only virtually excited and thus the requirement on the quality factor of the cavity is greatly relaxed
Simplified realization of two-qubit quantum phase gate with four-level systems in cavity QED
This is the published version, also available here: http://dx.doi.org/10.1103/PhysRevA.70.044303.We propose a method for realizing two-qubit quantum phase gate with 4-level systems in cavity QED. In this proposal, the two logical states of a qubit are represented by the two lowest levels of each system, and two intermediate levels of each system are utilized to facilitate coherent control and manipulation of quantum states of the qubits. The present method does not involve cavity-photon population during the operation. In addition, we show that the gate can be achieved using only two-step operations
Integrated Pest Management Practices for Rice Crops: Review of Indonesia and Taiwan
One of the new strategies to control rice pests that are at the same time more environmentally friendly is integrated pest management (IPM). IPM employs such methods as biological and mechanical controls, and botanicalpesticides. National and International resources have been used to developed IPM programs in some countries. Indonesia and Taiwan have used such programs to control rice pests. Biological control, botanical pesticides andsome mechanical control have been conducted in IPM program in both countries. However, assessing and comparing the effects of IPM programs are difficult because of the heterogeneity of the data due to differences in regions (e.g., climate, rainfall, soil structure), time periods, pest classes (e.g., insects, plant pathogens, weeds), and types of crops researched. In Indonesia using the recommended pesticides still be the last option for controlling the pests that reach an economic threshold. In 2011, recommended pesticides are applied about 981,628 ha of all rice crops. Other controls are the second pests control choosen in Indonesia. Other controls are consists of biological control (usingparasitoids and predators), microbial control (fungi, virus and bacteria) and natural plant extraction. Other controls reach about 464,854 ha of total rice crops in Indonesia. Mechanical controls are less applied than recommendedpesticides and other controls. Mechanical controls are including all controls before rice planting, such as harrowing land, killing rats, applying organic fertilizer, planting good varieties and cropping pattern. Mechanical controls reach about 84,920 ha of total rice crops in Indonesia. Taiwan also have similar development of rice IPM like Indonesia. In different counties, the farmers applied different IPM techniques. More farmers are independent to set up their rice pest control. Now, Taiwan have a significant progress in organic ric
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