Partly noiseless encoding of quantum information in quantum dot arrays against phonon-induced pure dephasing

We show that pure dephasing of a quantum dot charge (excitonic) qubit may be reduced for sufficiently slow gating by collectively encoding quantum information in an array of quantum dots. We study the role of the size and structure of the array and of the exciton lifetime for the resulting total error of a single-qubit operation.Comment: Final version; 10 pages, 8 figure

The brain in the humanities. The neural trends in the work of Stanislaw Przybyszewski

Wychodząc od refleksji o rozbieżnościach między humanistyką i nauką, autorka wskazuje na możliwość poszerzenia neuronauki o krytykę neurologiczną utworów literackich, opartą na kulturowej teorii kultury i koncepcji umysłu ucieleśnionego. Nową strategię stosuje wobec twórczości Stanisława Przybyszewskiego, poszerzając pole jej tradycyjnych odniesień, takich jak psychoanaliza, psychopatologia czy symbolika mistyczno-gnostyczna. Analizie poddaje listy, eseje i poematy z okresu berlińskiego, odwołując się do publicystyki z przełomu XIX i XX w. („Prawda”, „Zdrój”). Interesuje ją głównie przestrzeń wyobraźniowa i architektonika myślenia zaznaczająca się w utworze, różnicuje analizowane fragmenty pod względem stopnia referencji, dzieląc je na „neurologiczne stylizacje” (maszyna elektryczna, gangliony, węzeł syntetyczny, nici) i „neurologiczne kopie”. Ostatecznie, pisarskie refleksje na temat funkcjonowania mózgu prowadzą autorkę do wniosków o nowym obrazie podmiotu i dominacji metafor mózgowych w kulturze (kłącze).Starting from a reflection about differences between the humanities and science, the author indicates the possibility of expanding the neuroscience on neurological literature criticism, based on the cultural theory of culture and concepts of embodied mind. She applies this new strategy to the works of Stanislaw Przybyszewski, expanding its traditional fields of references such as psychoanalysis, psychopathology or mystical Gnostic symbolism. She analyzes letters, essays and poems from the Berlin period, referring to journalism at the turn of the nineteenth and twentieth century („Prawda”, „Zdroj”). She is interested mainly in imaginary space and tectonics of thinking, distinguished in the work, she distinguished the analyzed fragments in terms of the reference to „neurological styling” (an electric machine ganglia, synthetic knot, thread) and „neurological copies”. Finally, the writer’s reflections on the functioning of the brain, leads the author to the conclusion about the new image of the subject and domination of brain metaphors in culture (rhizome)

Aposiopesis albo figury myśli w dobie ucieleśnionego umysłu

The Author is interested in the states of becoming silent, discontinuing one’s utterance, which are associated with certain mechanisms of the functioning of the brain, as well as in the observation of such states in different artistic disciplines. Looking for an answer to the question how aposiopesis operates in words, sounds, and images, she analyzes pieces of music, poems (Zbigniew Herbert’s Pora), and examples of visual arts (Wojciech Pakmur’s paintings of the tango). In her reconstruction of the research field, the Author refers to rhetoric ( Jerzy Ziomek, Seweryna Wysłouch), the philosophy of language (Michel Foucault, Jean-François Lyotard), and neurophenomenology. The aim of the article is to suggest a new mode of reading that seeks inspiration and language in works from the field of neuropsychology (Maria Pąchalska), hermeneutic phenomenology (Mark Johnson), or neurology (António Damásio, Oliver Sacks). The Author’s analyses refer to Raoul Schrott and Arthur Jacobs’s concept (Gehirn und Gedicht, 2011), and the conclusions confirm that one should not look for a model (pattern) in the reception of art, but describe mental processes. The proposed mechanism of interpretation is most accurately reflected by the metaphor of dance improvisation, where one does not meditate on and then perform particular steps and gestures, but “thinks in motion.” This mode of reading emphasizes the spatial dimension of thought processes and their dynamic nature.The Author is interested in the states of becoming silent, discontinuing one’s utterance, which are associated with certain mechanisms of the functioning of the brain, as well as in the observation of such states in different artistic disciplines. Looking for an answer to the question how aposiopesis operates in words, sounds, and images, she analyzes pieces of music, poems (Zbigniew Herbert’s Pora), and examples of visual arts (Wojciech Pakmur’s paintings of the tango). In her reconstruction of the research field, the Author refers to rhetoric ( Jerzy Ziomek, Seweryna Wysłouch), the philosophy of language (Michel Foucault, Jean-François Lyotard), and neurophenomenology. The aim of the article is to suggest a new mode of reading that seeks inspiration and language in works from the field of neuropsychology (Maria Pąchalska), hermeneutic phenomenology (Mark Johnson), or neurology (António Damásio, Oliver Sacks). The Author’s analyses refer to Raoul Schrott and Arthur Jacobs’s concept (Gehirn und Gedicht, 2011), and the conclusions confirm that one should not look for a model (pattern) in the reception of art, but describe mental processes. The proposed mechanism of interpretation is most accurately reflected by the metaphor of dance improvisation, where one does not meditate on and then perform particular steps and gestures, but “thinks in motion.” This mode of reading emphasizes the spatial dimension of thought processes and their dynamic nature.

Phonon-assisted decoherence and tunneling in quantum dot molecules

We study the influence of the phonon environment on the electron dynamics in a doped quantum dot molecule. A non-perturbative quantum kinetic theory based on correlation expansion is used in order to describe both diagonal and off-diagonal electron-phonon couplings representing real and virtual processes with relevant acoustic phonons. We show that the relaxation is dominated by phonon-assisted electron tunneling between constituent quantum dots and occurs on a picosecond time scale. The dependence of the time evolution of the quantum dot occupation probabilities on the energy mismatch between the quantum dots is studied in detail.Comment: 4 pages, 2 figures, conference proceeding NOEKS10, to be published in Phys. Stat. So

The brain in the humanities. The neural trends in the work of Stanislaw Przybyszewski

Wychodząc od refleksji o rozbieżnościach między humanistyką i nauką, autorka wskazuje na możliwość poszerzenia neuronauki o krytykę neurologiczną utworów literackich, opartą na kulturowej teorii kultury i koncepcji umysłu ucieleśnionego. Nową strategię stosuje wobec twórczości Stanisława Przybyszewskiego, poszerzając pole jej tradycyjnych odniesień, takich jak psychoanaliza, psychopatologia czy symbolika mistyczno-gnostyczna. Analizie poddaje listy, eseje i poematy z okresu berlińskiego, odwołując się do publicystyki z przełomu XIX i XX w. („Prawda”, „Zdrój”). Interesuje ją głównie przestrzeń wyobraźniowa i architektonika myślenia zaznaczająca się w utworze, różnicuje analizowane fragmenty pod względem stopnia referencji, dzieląc je na „neurologiczne stylizacje” (maszyna elektryczna, gangliony, węzeł syntetyczny, nici) i „neurologiczne kopie”. Ostatecznie, pisarskie refleksje na temat funkcjonowania mózgu prowadzą autorkę do wniosków o nowym obrazie podmiotu i dominacji metafor mózgowych w kulturze (kłącze).Starting from a reflection about differences between the humanities and science, the author indicates the possibility of expanding the neuroscience on neurological literature criticism, based on the cultural theory of culture and concepts of embodied mind. She applies this new strategy to the works of Stanislaw Przybyszewski, expanding its traditional fields of references such as psychoanalysis, psychopathology or mystical Gnostic symbolism. She analyzes letters, essays and poems from the Berlin period, referring to journalism at the turn of the nineteenth and twentieth century („Prawda”, „Zdroj”). She is interested mainly in imaginary space and tectonics of thinking, distinguished in the work, she distinguished the analyzed fragments in terms of the reference to „neurological styling” (an electric machine ganglia, synthetic knot, thread) and „neurological copies”. Finally, the writer’s reflections on the functioning of the brain, leads the author to the conclusion about the new image of the subject and domination of brain metaphors in culture (rhizome)

Theory of phonon-mediated relaxation in doped quantum dot molecules

A quantum dot molecule doped with a single electron in the presence of diagonal and off-diagonal carrier-phonon couplings is studied by means of a non-perturbative quantum kinetic theory. The interaction with acoustic phonons by deformation potential and piezoelectric coupling is taken into account. We show that the phonon-mediated relaxation is fast on a picosecond timescale and is dominated by the usually neglected off-diagonal coupling to the lattice degrees of freedom leading to phonon-assisted electron tunneling. We show that in the parameter regime of current electrical and optical experiments, the microscopic non-Markovian theory has to be employed.Comment: Final extended version, 5 pages, 4 figure

Subprime borrowers, securitization and the transmission of business cycles

One of the roots of the recent global financial crisis has been seen in the design of subprime mortgage contract leading to high sensitivity of such type of loans to house price changes. The market of subprime loans, especially in the last years preceding the crisis, has been highly financed by securitization. The paper investigates how borrowers with subprime characteristics influence the transmission mechanism of business cycles in the economy and whether the securitization of subprime loans has a positive effect on the economy. The formal setup is a DSGE model with different types of borrowers and banks acting as financial intermediaries, in which households and entrepreneurs borrow against housing collateral. The economy is subject to four shocks: monetary, inflationary, preference and technology. It is shown that alone the existence of subprime borrowers does not make the economy more responsive to different shocks at the aggregate level (it has only redistributional effects) and that under certain circumstances the securitization of subprime loans (in form of residential mortgage backed securities) may lead to amplification of the business cycles

Phonon-assisted tunneling between singlet states in two-electron quantum dot molecules

We study phonon-assisted electron tunneling in semiconductor quantum dot molecules. In particular, singlet-singlet relaxation in a two-electron doped structure is considered. The influence of Coulomb interaction is discussed via comparison with a single electron system. We find that the relaxation rate reaches similar values in the two cases but the Coulomb interaction shifts the maximum rates towards larger separations between the dots. The difference in electron-phonon interaction between deformation potential and piezoelectric coupling is investigated. We show that the phonon-induced tunneling between two-electron singlet states is a fast process, taking place on the time scales of the order of a few tens of picoseconds.Comment: Final extended version, 8 pages, 9 figure