C. A. Chatzidimitriou-Dreismann

Elastic electron scattering from methane at high momentum transfer

We describe elastic electron scattering data at high momentum transfer (between ≈20 and ≈40 au) from methane and Xe. Under these conditions there is a significant recoil energy transferred to the target and electrons scattered elastically from methane are separated into two peaks: one due to electrons scattered from carbon, and one due to electrons scattered from hydrogen. The separation of these peaks is within a few per cent identical to what is expected for scattering from isolated C and H atoms. The peak due to electrons scattered from C, is again shifted compared to the peak of electrons scattered from Xe. The Xe, C and H peaks all have clearly different widths. The C and H peak areas are compared. Their relative intensity shows no substantial deviation (<10%) from what is expected based on either simple Rutherford cross sections, or state-of-the-art elastic scattering calculations. The latter observation is in strong contrast to electron scattering results from a gaseous equimolar H2–D2 mixture and from electron and neutron scattering results from polymers at similar momentum transfer.

Neutron Compton scattering anomaly verified with Rh-resonance foil

Compton scattering experiments with neutrons usually employ Au- or U-foils for energy selection of the scattered neutrons. A series of experiments on various H-containing materials have shown a large deficit in the scattering intensity of protons using Au-foils and it has been claimed that the anomalies arise from a faulty analysis of the data by neglecting effects of the tails of the Au-resonance lines. In the present experiments a Rh-103 resonance foil is used. It has considerably different resonance characteristics, but the H/metal ratio derived shows nearly the same anomalous value as with Au-foils. The present result therefore supports the existence of the mentioned anomalies.

Anomalous neutron Compton scattering cross sections in ammonium hexachlorometallates

The authors have performed neutron Compton scattering measurements on ammonium hexachloropalladate (NH(4))(2)PdCl(6) and ammonium hexachlorotellurate (NH(4))(2)TeCl(6). Both substances belong to the family of ammonium metallates. The aim of the experiment was to investigate the possible role of electronic environment of a proton on the anomaly of the neutron scattering intensity. The quantity of interest that was subject to experimental test was the reduction factor of the neutron scattering intensities. In both samples, the reduction factor was found to be smaller than unity, thus indicating the anomalous neutron Compton scattering from protons. Interestingly, the anomaly decreases with decreasing scattering angle and disappears at the lowest scattering angle (longest scattering time). The dependence of the amount of the anomaly on the scattering angle (scattering time) is the same in both substances (within experimental error). Also, the measured widths of proton momentum distributions are equal in both metallates. This is consistent with the fact that the attosecond proton dynamics of ammonium cations is fairly well decoupled from the dynamics of the sublattice of the octahedral anions PdCl(6) (2-) and TeCl(6) (2-), respectively. The hypothesis is put forward that proton-electron decoherence processes are responsible for the considered effect. Decoherence processes may have to do rather with the direct electronic environment of ammonium protons and not with the electronic structure of the metal-chlorine bond.

Neutron Compton scattering from the super proton conductor H3OSbTeO6 and polyethylene: a comparison of proton momentum distributions and reduced cross-sections

Neutron Compton scattering (NCS) results at large momentum transfers (q?60?130???1) obtained from the super proton conductor H3OSbTeO6 (powder at T = 295?K) are compared with those obtained from polyethylene (PE, foil at T = 295?K). The Compton profiles of protons in both systems are approximately Gaussians with equal widths, ?H?5???1, within experimental error, thus indicating that the effective (averaged over all spatial directions) Born?Oppenheimer (BO) potentials of protons in both systems are similar. In contrast, the anomalous decrease of scattering intensity from H in H3OSbTeO6 is only about 50% of that observed in PE. In a proposed theoretical frame (based on the violation of the BO approximation and attosecond proton?electron quantum entanglement) these comparative results reveal that the more mobile protons of the proton conductor are subject to a significantly faster decoherent quantum dynamics, which naturally causes a reduction of the anomaly in the scattering intensity. These new results may contribute to testing the validity of competing theoretical models. Connection with related NCS results from the super proton conductor Rb3H(SO4)2 is briefly made.

Proton momentum distribution and anomalous scattering intensities in a pseudo-spherical ammonium ion: a neutron Compton scattering study of (NH4)2PdCl6 and (NH4)2TeCl6

Neutron Compton scattering (NCS) measurements on ammonium hexachloropalladate and hexachlorotellurate were performed at room temperature. Proton scattering intensities and momentum distributions, as measured in the NCS experiment, have been compared with results expected from the impulse approximation (IA) for both systems. The measurement shows that scattering intensity from protons is anomalous even though their momentum distribution has a second moment that agrees very well with the ab initio calculation for an isolated pseudo-spherical NH(4)(+) ion in the ground vibrational state. Detailed data analysis shows that there is no extra (beyond the IA expected value) broadening or peak shift of proton momentum distribution due to ultra-fast kinetics of the Compton scattering process leading to anomalous scattering intensities. This is most probably due to highly symmetric local potential in the NH(4)(+). Presented results have interesting implications for further theoretical work in the field.

A new data treatment scheme for integrated intensities in neutron Compton scattering

A new data reduction scheme is presented for time-of-flight data collected in neutron Compton scattering experiments with the aim of obtaining the scattering intensities. The method proposed is a single number approach as it makes use of the count rates detected in the individual time-of-flight channels. The most convenient seems to be the variant of the method where time-of-flight channels are chosen corresponding to centers of recoil peaks of individual masses. With such a choice of time-of-flight channels, the method presented is more robust against unwanted background signals and noise than the method widely used in NCS studies based on fitting entire time-of-flight band shapes in the framework of the convolution approximation. Moreover, it should perform better than the model-free Dorner method as it does not require the numerical integration of the signal, which is also sensitive to baseline and noise. As an example of the performance of the new method, polyethylene data are treated and compared to results obtained previously using conventional data reduction and the model-free method proposed by Dorner. It is shown that all three data reduction schemes lead to the same results for the scattering intensities of protons in polyethylene, thus strengthening the conclusion about the anomalous scattering cross-section of protons in this substance. In the future the new data reduction scheme can be used to treat the data from other experiments where the conventional NCS data treatment and/or Dorner method fail due to noise and/or unwanted background signals present in the time-of-flight spectra.

Quantum Entanglement and Decoherence Due to Coupling of Protons to Electronic Environment

In recent years many scattering experiments have been performed on hydrogen containing materials which showed a scattering behavior different from the expectation according to standard theories. These scattering anomalies are attributed to the existence of short lived protonic quantum entanglement (QE) and decoherence. It was suggested that also electronic degrees of freedom might be involved in the anomalous scattering behavior. Here, the influence of the electronic structure surrounding the H atoms in different materials on the neutron scattering cross section of hydrogen is investigated. Experimental neutron Compton scattering results of H2O / D2O mixtures and LiH at different temperatures are presented. Also LaH2 which exhibits metallic properties and LaH3 which is an insulator — i.e., both materials have different electronic structures — are investigated at room temperature. It is found that different electronic environments lead to different scattering behavior, thus strongly supporting the supposition that the electronic degrees of freedom are engaged in the protonic attosecond QE and the decoherence process. Furthermore, we present very recent results of experimental tests of the data analysis procedure which have been criticized recently. We show that the data analysis procedure is correct and criticisms are irrelevant for the experimental setup used in our NCS experiments.

Attosecond Effects in Scattering of Neutrons and Electrons from Protons

Application of the neutron Compton scattering (NCS) technique — which operates in the sub-femtosecond timescale — to various materials yields results which indicate the presence of short-lived quantum entanglement between protons and electrons, and reveals novel aspects of attosecond dynamics of chemical bonds, e.g., breaking of covalent C - H bonds. The following striking phenomenon has been revealed: the scattering intensity from H is anomalously decreased — about 20 – 30% of the protons (H-atoms) seem to “disappear”. Here we present experimental results from water and H2O - D2O mixtures, liquid benzene, amphiphiles (2-isobutoxyethanol dissolved in D2O), liquid hydrogen and H2 - D2 mixtures, and a solid polymer (formvar). Very recently this phenomenon has been confirmed with an independent method: electron Compton scattering from nuclei (ECS). Comparative NCS and ECS results from formvar are presented.

Schrödinger’s Cat States of Protons in Condensed Matter

7Laser Physics & Quantum Optics, Royal Institute of Technology (KTH), AlbaNova, Roslagstullsbacken 21, SE-10691 Stockholm, Sweden The development of the experimental and theoretical work on Proton entanglement and decoherence in condensed matter is recent but yet has a rich history starting with the pioneering work of C. A. Chatzidimitriou-Dreismann et al. [Chatzidimitriou-Dreismann 1997 (a)]. There, the authors presented experimental results of neutron Compton scattering (NCS) from H2O / D2O mixtures showing a striking effect manifested by anomalous shortfall of the scattering cross section of the protons. It has been claimed [Chatzidimitriou-Dreismann 1997 (a)] that these results provided for the first time direct evidence for the existence of short-lived nuclear quantum entanglement,proton / neutron. This experiment was followed by another one on a biologically important material, , urea dissolved in H2O / D2O mixtures, which showed results different than those of the pure solvent [Chatzidimitriou-Dreismann 1999]. A new dynamical aspect based on previous work by V. F. Sears [Sears 1984] and G. I. Watson [Watson 1996] was introduced to the data interpretation by the work of E. B. Karlsson et al. [Karlsson 1999] on niobium hydride. While the cross section anomalies found in the previous work [Chatzidimitriou-Dreismann 1997 (a); Chatzidimitriou-Dreismann 1999] were independent of the ex-

Scientific Review: Neutron Compton Scattering Unveils Short-Lived Quantum Entanglement of Hydrogen in Condensed Matter

Multiparticle quantum entanglement (QE) and its dynamical properties are in the focus of several experimental and theoretical fields of modern physics and engineering (e.g., quantum optics, quantum computation, quantum cryptography, and teleportation). This is due to the potential applicability of QE for quantum computers and quantum information technology. If the quantum entangled particles are sufficiently isolated from their environment, coherence can persist for long times and quantum phenomena are revealed. However, under realistic conditions, the entangled objects are continuously interacting with their environment. Thus, coherence is lost and classicality emerges. This process is called decoherence [1] and represents the main problem for the realization of a quantum computer.