Infrared catastrophe and tunneling into strongly correlated electron systems: Exact solution of the x-ray edge limit for the 1D electron gas and 2D Hall fluid

In previous work we have proposed that the non-Fermi-liquid spectral properties in a variety of low-dimensional and strongly correlated electron systems are caused by the infrared catastrophe, and we used an exact functional integral representation for the interacting Green's function to map the tunneling problem onto the x-ray edge problem, plus corrections. The corrections are caused by the recoil of the tunneling particle, and, in systems where the method is applicable, are not expected to change the qualitative form of the tunneling density of states (DOS). Qualitatively correct results were obtained for the DOS of the 1D electron gas and 2D Hall fluid when the corrections to the x-ray edge limit were neglected and when the corresponding Nozieres-De Dominicis integral equations were solved by resummation of a divergent perturbation series. Here we reexamine the x-ray edge limit for these two models by solving these integral equations exactly, finding the expected modifications of the DOS exponent in the 1D case but finding no changes in the DOS of the 2D Hall fluid with short-range interaction. We also provide, for the first time, an exact solution of the Nozieres-De Dominicis equation for the 2D electron gas in the lowest Landau level.Comment: 6 pages, Revte

Electric Field Modulation of Galvanomagnetic Properties of Mesoscopic Graphite

Electric field effect devices based on mesoscopic graphite are fabricated for galvanomagnetic measurements. Strong modulation of magneto-resistance and Hall resistance as a function of gate voltage is observed as sample thickness approaches the screening length. Electric field dependent Landau level formation is detected from Shubnikov de Haas oscillations in magneto-resistance. The effective mass of electron and hole carriers has been measured from the temperature dependant behavior of these oscillations.Comment: 4 pages, 4 figures included, submitted to Phys. Rev. Let

Can AI Become an Information Literacy Ally? A Survey of Library Instructor Perspectives on ChatGPT

Libraries can play a role in navigating the AI era by integrating these tools into information literacy (IL) programs. To implement generative AI tools like ChatGPT effectively, it is important to understand the attitudes of library professionals involved in IL instruction toward this tool and their intention to use it for instruction. This study explored perceptions of ChatGPT using survey data that included acceptance factors and potential uses derived from the emerging literature. While some librarians saw potential, others found it too unreliable to be useful; yet the vast majority imagined utilizing the tool in the future

ChatGPT is a Liar and other Lessons Learned from Information Literacy Instructors

Wondering where generative artificial intelligence (AI) fits in information literacy instruction? This session will share findings from a recent survey of library professionals on how they are already teaching about and using AI powered ChatGPT in information literacy instruction and where they see potential opportunities and areas of concern. Survey analysis will include information about attitudes, current and anticipated use, and descriptions of teaching methods that leverage the technology. As we navigate the survey results, attendees will have the opportunity to share their own perspectives on the same questions via live polling. We will then turn to attendees to share their experiences and the challenges they have found in addressing the needs of their library communities as they explore applications of AI in their research, instruction, writing, and creative endeavors. As we explore the topic we will cover issues ranging from what generative AI is and is not, “hallucinated” information, deep fakes, misinformation, biased training data, documenting use of AI, privacy, copyright and costs

Continuous Beam Steering Realized by Tunable Ground in a Patch Antenna

A continuously steerable patch antenna employing liquid metal is presented. The proposed antenna employs a novel tunable ground plane together with parasitic steering to steer the direction of the main beam. The tunable ground plane consists of a permanent region, made from copper, and two tunable regions formed from liquid metal. The liquid metal channels were fabricated using 3D printing technology. By continuously injecting liquid metal into channels, the proposed patch antenna can provide continuous beam steering from -30 to +30 in the elevation plane, while achieving low side lobe level performance combined with low scan loss performance. Such an approach has never been tried before and it is only possible due to the unique properties of liquid metal. To the best of the authors’ knowledge, this is the first time that tunable ground plane has been used for a patch antenna to achieve continuous beam steering. The proposed antenna operates at 5.3 GHz. The antenna is fabricated and measured. Measurement results agree well with the simulation results and validate the effectiveness of the proposed beam steering technique. The proposed antenna has a measured gain of 8.1 dBi at 5.3 GHz and wide bandwidth performance. The tunable ground technique proposed in this work will find numerous applications within future wireless communications systems