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Jiri Tolar

Publications and source records attributed to Jiri Tolar.

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CNOT on Polarization States of Coherent Light

We propose a CNOT gate for quantum computation. The CNOT operation is based on existence of triactive molecules, which in one direction have dipole moment and cause rotation of the polarization plane of linearly polarized light and in perpendicular direction have a magnetic moment. The incoming linearly polarized laser beam is divided into two beams by beam splitter. In one beam a control state is prepared and the other beam is a target. The interaction of polarized states of both beams in a solution containing triactive molecules can be described as interaction of two qubits in CNOT.

quant-ph

Survey of an approach to quantum measurement, classical properties and realist interpretation problems

The paper gives a systematic review of the basic ideas of (non-relativistic) quantum mechanics including all changes that result from previous work of the authors. This shows that the new theory is self-consistent and (in certain sense) complete. The most important changes are: 1) A new realist interpretation of quantum mechanics based on the observation that there are enough objective properties of quantum systems if one looks for them elsewhere than among values of observables. This enables us to introduce the notion of quantum object. 2) Classical systems are defined as macroscopic quantum objects in states close to maximum entropy. For classical mechanics, new states of such kind are introduced, the so-called maximum-entropy packets, and shown to approximate classical dynamics better than Gaussian wave packets. 3) A new solution of quantum measurement problem is proposed for measurements that are performed on microsystems. First, it is assumed that readings of registration apparatuses are always signals from detectors. This implies restrictions on what is observable. Second, an application of the cluster separability principle leads to the key notion of the paper: the separation status of microsystems. The processes of preparation and registration include changes of separation status. A crucial observation is that standard quantum mechanics does not prescribe the evolution during such changes. This gap can be filled by new rules without contradicting the rest of quantum mechanics. As an example of such a new rule, Beltrametti-Cassinelli-Lahti model of measurement is modified and shown then to satisfy both the probability-reproducibility and the objectification requirements.

quant-ph

Can differently prepared mixed states be distinguished?

A measurement has been proposed by B. d'Espagnat that would distinguish from one another some ensembles that are differently prepared but correspond to the same density matrix. Here, the idea is modified so that it becomes applicable to much more general situations. The method is illustrated in simple examples. Some matter of concern might then be that information could be transmitted by methods based on our idea in the EPR kind of experiments. A simple proof is given that this is impossible.

quant-ph