Incompressible States in Double Quantum Dots

Incompressible (magic) states of vertically coupled quantum dots submitted to strong magnetic fields such that only the lowest Landau level is relevant are studied within an exact diagonalization calculation for N=3, 5 and 6, electrons. We find that the sequences of total angular momentum M for which incompressible states exists depend on the interplay between the inter-dot hopping parameter \Delta_t and the inter-dot distance d. For d of the order of the magnetic length and for all values of \Delta_t, we conclude that, in contrast to previous claims, the incompressible states appear at magic values of M which do not differ from those obtained for a single dot, namely M=N(N-1)/2+jN where j is a positive integer number. For large inter-dot distance and simultaneously small inter-dot hopping parameter, new sequences of magic values of $M$ are observed. These new sequences can be easily understood in terms of a transition regime towards a system of two decoupled single dots. However, important differences in the nature of the incompressible ground states are found with respect to those of a single dot.Comment: 23 pages, 11 figures; discussion improved, references added, journal versio

QUADRUPOLE SPLITTING OF MOSSBAUER LINES DUE TO DEFECTS IN CO0

The Fe3+ lines observed in CoO Mossbauer sources may arise from the decay of Co3+ ions associated with cation vacancies in the crystal. These defects produce an electric-field gradient that causes a quadrupole splitting of the resonance line and that can, in principle, distinguish between different types of defects. The calculation of the quadrupole splitting at Fe2+ and Fe3+ sites near various vacancy clusters includes the relaxation of the lattice about the defect. This lattice polarisation and distortion is shown to be extremely important, since simple calculations based on perfect ion positions give very different field gradients at neighbouring sites. The results compared with the experiments available and the quadrupole splittings observed are close to those predicted by a vacancy model

...and Poldy not Irish enough... : Nationalism and Ideology in James Joyce\u27s Ulyssess

Following Louis Althusser‘s and Slavoj Zizek‘s analyses of ideology, then, I want to explore the representations of Stephen Dedalus and Leopold Bloom in terms of their response to the hegemonic discourses espoused by Catholicism and Nationalism (both linked to Empire). With this intention, I will concentrate on Episode Ten, ― The Wandering Rocks, since from the characters‘ actions and conversations as they intersect in the streets of Dublin we can extrapolate the ideological narratives in which Ireland was immersed at the time. I suggest that the personal struggle for ideological liberation Joyce initiated with Stephen Dedalus in A Portrait necessarily led to the development of Leopold Bloom because, by the beginning of Ulysses, it is apparent that Stephen is still too susceptible to the Roman Catholic ideology of his formative years. Even though the young Dedalus fights to overcome his limitations, precisely because of his upbringing he cannot rise above the principles inculcated by his family and his Jesuit education. Stephen thus becomes too partial a figure for Joyce‘s project, so a character like the Jewish salesman emerges as the main protagonist of this odyssey. Bloom‘s ― multiplicity visibly sets him apart from the ― real Irish men in Ulysses. At the same time, because of his plurality, Bloom manages to free himself from the artificial binary-pattern mentality that fixes the other male characters inside an ideology that can only perpetuate imperial exploitation

Hall response of interacting bosonic atoms in strong gauge fields: from condensed to FQH states

Interacting bosonic atoms under strong gauge fields undergo a series of phase transitions that take the cloud from a simple Bose-Einstein condensate all the way to a family of fractional-quantum-Hall-type states [M. Popp, B. Paredes, and J. I. Cirac, Phys. Rev. A 70, 053612 (2004)]. In this work we demonstrate that the Hall response of the atoms can be used to locate the phase transitions and characterize the ground state of the many-body state. Moreover, the same response function reveals within some regions of the parameter space, the structure of the spectrum and the allowed transitions to excited states. We verify numerically these ideas using exact diagonalization for a small number of atoms, and provide an experimental protocol to implement the gauge fields and probe the linear response using a periodically driven optical lattice. Finally, we discuss our theoretical results in relation to recent experiments with condensates in artificial magnetic fields [ L. J. LeBlanc, K. Jimenez-Garcia, R. A. Williams, M. C. Beeler, A. R. Perry, W. D. Phillips, and I. B. Spielman, Proc. Natl. Acad. Sci. USA 109, 10811 (2012)] and we analyze the role played by vortex states in the Hall response.Comment: 10 pages, 7 figure

Frankly Speaking, the men that is now is only all pallaver and what they can get our of you : Migration and White Slavery in Argentina in Joyce\u27s Eveline

This article analyzes James Joyce’s “Eveline” (1904), looking at the moral panic about “white slavery” in Europe and South America. The article especially focuses on Argentina, the foremost recipient of trafficked women between 1880 and 1930 (and, of course, Joyce’s destination choice for Eveline). By looking at Frank, the sailor who intends to take Eveline to Buenos Aires, this article explores the possible links between Joyce’s story and the sex trafficking industry thriving in Buenos Aires through the Jewish criminal association Zwi Migdal. Frank’s representation allows us to draw this connection because his behavior with Eveline coincides with the seduction and recruiting methods employed by Zwi Migdal procurers. This work adds to Hugh Kenner’s skeptical reading of the sailor and Katherine Mullin’s analysis of Joyce and white slavery discourses by suggesting that, in light of the historical situation in Argentina and Joyce’s hyper-analyzed ambiguities, Frank could be a Zwi Midgal recruiter and Eveline a potential sex slave

Commodified Anatomies: Disposable Women in Postcolonial Narratives of Sexual Trafficking/Abduction

This dissertation explores postcolonial fiction that reflects the structural situation of a genocidal number of third-world women who are being trafficked for sexual purposes from postcolonial countries into the global north—invariably, gender, class and race play a crucial role in their exploitation. Above all, these women share a systemic disposability and invisibility, as the business relies on the victim’s illegality and criminality to generate maximum revenues. My research suggests that the presence of these abject women is not only recognized by ideological and repressive state apparatuses on every side of the trafficking scheme (in the form of governments, military establishments, juridical systems, transnational corporations, etc.) but is also understood as necessary for the current neoliberal model to thrive undisturbed by ethical imperatives. Beginning with the turn of the twentieth century, then, I analyze sexual slavery transnationally by looking at James Joyce’s “Eveline,” Therese Park’s A Gift of the Emperor, Mahasweta Devi’s “Douloti the Bountiful,” Amma Darko’s Beyond the Horizon, Chris Abani’s Becoming Abigail, and Roberto Bolaño’s 2666, concentrating on the political, economic, and social discourses in which the narratives are immersed through the lens of Marxist, feminist, and postcolonial theory. By interrogating these postcolonial narratives, my project reexamines the sex slave-trafficker-consumer triad in order to determine the effect of each party’s presence or absence from the text and the implications in terms of the discourses their representations may tacitly legitimize. At the same time, this work investigates the type of postcolonial stories the West privileges and the reasons, and the subjective role postcolonial theory plays in overcoming subaltern women’s exploitation within the current neocolonial context. Overall, I interrogate the role postcolonial literature plays as a means of achieving (or not) social change, analyze the purpose of artists in representing exploitative situations, identify the type of engagement readers have with these characters, and seek to understand audiences’ response to such literature. I look at authors who have attempted to discover fruitful avenues of expression for third-world women, who, despite increasingly constituting the bulk of the work force worldwide, continue to be exploited and, in the case of sex trafficking, brutally violated

On Writing Transnational Migration in On Black Sisters’ Street (2009) and Better Never Than Late (2019): An Interview with Chika Unigwe

This interview with Nigerian writer Chika Unigwe, conducted in early 2020, addresses the ethics and aesthetics of representing sex trafficking and transnational migration in her award-winning novel On Black Sisters’ Street (2009) and her latest short story collection Better Never Than Late, which appeared in the US in 2020. The author discusses the discourse on migration and trafficking in both works, bringing much-needed nuance to the conversation. She pays particular attention to issues of “agency” and “vulnerability”, as well as authenticity, stereotyping, the “white gaze”, the publishing industry, and the recent controversy on Jeanine Cummins’s American Dirt (2020). Drawing from her own personal story, Unigwe also talks in depth about the stylistic choices she made in depicting the immigrant experience in the global north and the difficulty of representing rape and trauma in fiction