Considerable attention has been paid to dating the earliest appearance of hominins outside Africa. The earliest skeletal and artefactual evidence for the genus Homo in Asia currently comes from Dmanisi, Georgia, and is dated to approximately 1.77-1.85 million years ago (Ma). Two incisors that may belong to Homo erectus come from Yuanmou, south China, and are dated to 1.7 Ma; the next-oldest evidence is an H. erectus cranium from Lantian (Gongwangling)-which has recently been dated to 1.63 Ma-and the earliest hominin fossils from the Sangiran dome in Java, which are dated to about 1.5-1.6 Ma. Artefacts from Majuangou III and Shangshazui in the Nihewan basin, north China, have also been dated to 1.6-1.7 Ma. Here we report an Early Pleistocene and largely continuous artefact sequence from Shangchen, which is a newly discovered Palaeolithic locality of the southern Chinese Loess Plateau, near Gongwangling in Lantian county. The site contains 17 artefact layers that extend from palaeosol S15-dated to approximately 1.26 Ma-to loess L28, which we date to about 2.12 Ma. This discovery implies that hominins left Africa earlier than indicated by the evidence from Dmanisi.

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Chiral photonics has emerged as a key technology for future optoelectronics, such as quantum information and encryption, by making use of photonic waves from enantiomeric structures. An inevitable challenge for realizing such chiral optoelectronics is the development of near-infrared circularly polarized (NIR CP) light-sensing photodetectors that convert optical power and circular polarization direction into distinguishable electrical signals. Herein, a simple and promising strategy for high-performance NIR CP light-sensing organic phototransistors (NIR CPL-OPTRs) applicable to highly secure optoelectronic encryption is proposed. By directly assembling a standalone cholesteric liquid-crystal network film in a thin-film NIR CPL-OPTR, remarkable responsivity and distinguishability are achieved. The synergetic effect of amplification of the photocurrent signal by the applied electric field and improved light absorption by the reduced reflection in the multilayered structure leads to high responsivity. As a proof-of-concept, the chiral phototransistor arrays are demonstrated as a physically unclonable function device and exhibit enhanced cryptographic characteristics.

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