Data-pattern tomography of entangled states

Abstract

We discuss the data-pattern tomography for reconstruction of entangled states of light. We show that for a moderate number of probe coherent states it is possible to achieve high accuracy of representation not only for single-mode states but also for two-mode entangled states. We analyze the stability of these representations to the noise and demonstrate the conservation of the purity and entanglement. Simulating the probe and signal measurements, we show that systematic error inherent for representation of realistic signal response with finite sets of responses from probe states still allows one to infer reliably the signal states preserving entanglement.

Quantum teleportation of qudits by means of generalized quasi-Bell states of light

“…and can be calculated numerically from Eqs. (22) and (23) for any input state, defined by the choice of coefficients Q l . We calculate the success probability for a RICS |c q , defined by Eq.…”

“…Splitting these superpositions in two modes, one obtains entangled coherent states [17,18,19,20,21,22,23]. The states of the first class create in this way quasi-Bell states [18], having the same structure as usual Bell states of two qubits, but with two non-orthogonal coherent states as basis for each mode.…”

“…The states of the first class create in this way quasi-Bell states [18], having the same structure as usual Bell states of two qubits, but with two non-orthogonal coherent states as basis for each mode. These states can be applied to quantum metrology [21], quantum tomography [22] and probabilistic quantum teleportation * Corresponding author Email address: dmitri.horoshko@univ-lille.fr (D. B. Horoshko) [19,20], which is a key element of coherent state quantum computation. While traveling-wave superpositions can be rather easily split by a beam-splitter, cavity fields require a more sophisticated technique, realized only recently for two coupled microwave cavities [23].…”

Nonholonomic tomography. II. Detecting correlations in multiqudit systems

“…Equations (11) and (12) represent weaker forms of effective independence than Equation (10). One should think of them as potential factorizations of the data which may or may not exist.…”

“…[3] Any practice which takes into account SPAM errors will be generically referred to as SPAM tomography. Several works have come out in SPAM tomography [3][4][5][6][7][8][9][10] particular to the task of making estimates in spite of such conditions, all of which speak to the notion of a "self-consistent tomography." Of course, such works assume that any and all SPAM errors are uncorrelated.…”