Fall 2017

Entangled states are a key resource in fundamental quantum physics, quantum cryptography and quantum computation. Unfortunately, these states are fragile and easily degrade by unwanted interactions with a dissipative environment. Thus, it has generally been assumed that the creation of such states requires the system to have minimal dissipation and decoherence. However, some recent theoretical studies have shown that dissipative interactions combined with appropriately chosen drives can be employed to preserve coherence, and in particular to stabilize entanglement...

The Weyl semimetal is a new topological state of matter discovered recently. It exhibits not only topologically protected surface states (similar to the topological insulator), but also fascinating charge and spin transport properties in the bulk. In this talk, I will introduce a new type of Weyl semimetal in chiral antiferromagnetic (AFM) materials, Mn3Ge and Mn3Sn [1]. They show Weyl points where bands cross linearly with large Berry phases in the band structure [2], giving rise to large anomalous Hall effect observed in recent experiments [3]. Furthermore, we have...

The ability to engineer and manipulate different types of quantum mechanical objects allows us to take advantage of their unique properties and create useful hybrid technologies. Thus far, complex quantum states and exquisite quantum control have been demonstrated in systems ranging from trapped ions to superconducting resonators. Recently, there have been many efforts to extend these demonstrations to the motion of complex, macroscopic objects. These mechanical objects have important applications as quantum memories or transducers for measuring and connecting different...

Topological materials and two-dimensional (2D) materials (including graphene) have become among the most actively studied systems in condensed matter physics emerged in the last decade, as also reflected in two recent physics Nobel prizes (2016 and 2010). These classes of materials, with significant overlap and connection between them, have also received attention beyond condensed matter physics, ranging from high-energy physics to electronics industries. These materials bring unprecedented freedom to realize and engineer novel electronic bandstructures (kinetic energy-...

Organic and organic-based materials are broadly attractive as a complement to inorganic materials due to their relative ease of fabrication, mechanical flexibility, and the ability to tune molecular properties. These benefits have been slow to accrue to the fields of spintronics and magnonics due to the combined challenges of interfacing organic and inorganic materials and the lack of “native” organic or organic-based magnetic materials with suitable DC and microwave magnetic properties. Here I will present a series of recent breakthroughs in the synthesis, device...