Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userArbitrary-dimensional teleportation of optical number states with linear optics
138
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Quantum state teleportation of optical number states is conspicuously absent from the list of experimental milestones achieved to date. Here we demonstrate analytically a teleportation scheme with fidelity $100%$ for optical number states of arbitrary dimension using linear optical elements only. To this end, we develop an EPR source to supply Bell-type states for the teleportation, and show how the same set-up can also be used as a Bell-state analyser (BSA) when implemented in a time-reversal manner. These two aspects are then brought together to complete the teleportation protocol in a scheme that can deliver perfect fidelity, albeit with an efficiency that decays exponentially as the occupation of the number states increases stepwise. The EPR source and BSA schemes both consist of two optical axes in a symmetrical V-shape experimental layout, along which beam-splitters are placed cross-beam fashion at regular intervals, with their transmittivities treated as variables for which the values are calculated ad hoc. In particular, we show the full treatment for the case of qutrit teleportation, and calculate the transmittivity values of the beam splitters required for teleporting qubits, qutrits, qupentits, quheptits and qunits. The general case for arbitrary-dimensional number state teleportation is demonstrated through a counting argument.
rate research
Read More
Future quantum computers are likely to be expensive and affordable outright by few, motivating client/server models for outsourced computation. However, the applications for quantum computing will often involve sensitive data, and the client would like to keep her data secret, both from eavesdroppers and the server itself. Homomorphic encryption is an approach for encrypted, outsourced quantum computation, where the clients data remains secret, even during execution of the computation. We present a scheme for the homomorphic encryption of arbitrary quantum states of light with no more than a fixed number of photons, under the evolution of both passive and adaptive linear optics, the latter of which is universal for quantum computation. The scheme uses random coherent displacements in phase-space to obfuscate client data. In the limit of large coherent displacements, the protocol exhibits asymptotically perfect information-theoretic secrecy. The experimental requirements are modest, and easily implementable using present-day technology.
We demonstrate a sequence of two quantum teleportations of optical coherent states, combining two high-fidelity teleporters for continuous variables. In our experiment, the individual teleportation fidelities are evaluated as F_1 = 0.70 pm 0.02 and F_2 = 0.75 pm 0.02, while the fidelity between the input and the sequentially teleported states is determined as F^{(2)} = 0.57 pm 0.02. This still exceeds the optimal fidelity of one half for classical teleportation of arbitrary coherent states and almost attains the value of the first (unsequential) quantum teleportation experiment with optical coherent states.
We derive the maximum fidelity attainable for teleportation using a shared pair of d-level systems in an arbitrary pure state. This derivation provides a complete set of necessary and sufficient conditions for optimal teleportation protocols. We also discuss the information on the teleported particle which is revealed in course of the protocol using a non-maximally entangled state.
The general transformation of the product of coherent states $prod_{i=1}^N|alpha_i>$ to the output state $prod_{i=1}^M|beta_i>$ ($N=M$ or $N eq M$), which is realizable with linear optical circuit, is characterized with a linear map from the vector $(alpha^{ast}_1,...,alpha^{ast}_N)$ to $(beta^{ast}_1,...,beta^{ast}_M)$. A correspondence between the transformations of a product of coherent states and those of a single photon state is established with such linear maps. It is convenient to apply this linear transformation method to design any linear optical scheme working with coherent states. The examples include message encoding and quantum database searching. The limitation of manipulating entangled coherent states with linear optics is also discussed.
Using only linear optical elements, the creation of dual-rail photonic entangled states is inherently probabilistic. Known entanglement generation schemes have low success probabilities, requiring large-scale multiplexing to achieve near-deterministic operation of quantum information processing protocols. In this paper, we introduce multiple techniques and methods to generate photonic entangled states with high probability, which have the potential to reduce the footprint of Linear Optical Quantum Computing (LOQC) architectures drastically. Most notably, we are showing how to improve Bell state preparation from four single photons to up to p=2/3, boost Type-I fusion to 75% with a dual-rail Bell state ancilla and improve Type-II fusion beyond the limits of Bell state discrimination.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
