Qin-Qin Lu

Our understanding of glass production in Eurasia has been built mostly on evidence from Europe and the Mediterranean. Here, we investigate the occurrence and organization of plant-ash glass production in the eastern continental Islamic region, focusing on an 11th–12th century assemblage unearthed in Shadyakh, Nishapur, Iran. Through Sr-Nd isotope analysis and by examining geochemical contexts and mixing patterns, we find that distinct silica and ash sources originating from Tigris-Euphrates Basin, Central Asia, and potentially Iran were used to make these objects. Zagros-derived silica and Central-Asian-type silica were likely important silica sources for Islamic plant-ash glasses from east of the Tigris. Furthermore, we show that Central Asian glass can be characterized by chemical and isotopic signatures, while Iranian glass may exhibit overlapping signatures with glass from neighboring regions. The plant-ash glass industry in Islamic-period West and Central Asia likely thrived by exploiting and sharing diverse, regionally characteristic raw material sources.

Natron-based glass was a vital part of material culture in the Mediterranean and Europe for nearly two millennia, but natron glass found elsewhere on the Eurasian Continent has not received adequate discussion, despite its influence on ancient Asian glass. Here we present a new interpretation of natron glass finds from both the West and the East. After establishing the compositional types and technological sequence of Mediterranean natron glass (eighth-second century BCE) using trace elements, we report the analysis of a mid-1st millennium BCE glass bead from Xinjiang, China, which was likely made with Levantine raw glass, and identify common types of stratified eye beads in Eurasia based on a compositional and typological comparison. Combining these findings, we propose that a considerable number of Mediterranean natron glass products had arrived in East Asia at least by the fifth century BCE, which may have been a contributing factor in the development of native Chinese glass-making. The swift diffusion of natron glass across Eurasia in the 1st millennium BCE was likely facilitated by a three-stage process involving maritime and overland networks and multiple forms of trade and exchange, indicating a highly adaptable and increasingly efficient transcontinental connection along the 'Proto-Silk Road'. Past interregional interactions in the Eurasian Continent shaped our world in numerous ways. It is critically important to understand how such interactions evolved in time, extended to larger areas, and exerted increasing influence over cultures. Recent studies have revealed prehistoric connections in Eurasia based on evidence such as human migration 1-3 , the transmission of domesticated crops 4,5 , and the diffusion of pottery 6 and metallurgical 7 technologies. However, before and during much of the Bronze Age, the spread of population, materials, and innovations remained generally time-consuming, suggesting limited intensity of long-range communications. For instance, wheat did not reach the lower Yellow River in China until six millennia after its domestication in West Asia 8,9. This situation had changed by the second century BCE, when Chinese Warring States silk, mirrors and lacquer appeared in contemporaneous burials in Siberia and Inner Asia 10 , and remote regions were recorded in Roman and Chinese literature. At the dawn of a surge in transcontinental material exchange, the Han Dynasty's envoy Zhang Qian was sent for missions into Asia's heartland in the late second century BCE, an event conventionally considered as the beginning of the historical Silk Road. The preceding period, i.e., the 1st millennium BCE, is therefore vital for the decisive acceleration and integration of the long-distance interactions in Eurasia. Man-made glass is one of the truly transnational products of civilization, and can be used to investigate long-distance interactions. Glass had a diverse history of origin and dispersal. Soda glass was first manufactured in the Near East, and subsequently in Europe, Central Asia, and South Asia. Potash glass can be found in South, Southeast, and East Asia, as well as in Europe. Lead-barium glass first appeared in China and was also found in other parts of East Asia 11,12. The emergence of glass-making technology in East Asia during the 1st millennium BCE is an open question. Archaeological investigations of early Chinese glass have revealed the presence of all OPEN

A theoretical study of interacting bosons in a periodic optical lattice is presented. Instead of the commonly used tight-binding approach (applicable near the Mott insulating regime of the phase diagram), the present work starts from the exact single-particle states of bosons in a cubic optical lattice, satisfying the Mathieu equation, an approach that can be particularly useful at large boson fillings. The effects of short-range interactions are incorporated using a self-consistent Hartree- Fock approximation, and predictions for experimental observables such as the superfluid transition temperature, condensate fraction, and boson momentum distribution are presented.