The first signature of Majorana physics, identified experimentally at TU Delft in 2012, focused on a characteristic conductance peak at zero voltage. It bore many signatures of Majorana zero modes, but had a sizable background signal that obscured how the peak arose out of coalescing Andreev bound states. Recently, Mingtang Deng and a Station Read more
Majorana devices will generally be much more complicated than the single-junction or single quantum dot Majorana devices that have been realized in the literature so far. (See https://arxiv.org/abs/1610.05289 by the Station Q team for examples of complex devices.) Recently, a first step toward complex multi-gated Majorana devices—a Majorana double quantum wire—was realized by Daniel Sherman and Read more
Last year saw a materials breakthrough, with the realization of a two-dimensional heterostructure combining superconductor and semiconductor layers. (See journals.aps.org/prb/abstract/10.1103/PhysRevB.93.15540.) Now, as shown in a recent report, this material has been used to study interference effects controlled by magnetic fields in a Josephson junction made from this material. Anomalous interference reveals properties of the semiconductor in Read more
Generation of reversible circuits from high-level code is an important problem in the compilation flow of quantum algorithms to lower-level hardware. The instantiation of quantum oracles in particular will require mapping classical circuits to a reversible implementation. Existing tools compile and optimize reversible circuits for various metrics, such as the overall circuit size or the Read more
In the paper, “Double semions in arbitrary dimension,” published in Communications in Mathematical Physics, Michael Freedman and Matthew Hastings present a new construction of topological phases of matter in higher dimensions, generalizing the double semion theory in two dimensions. This theory is distinct from the Dijkgraaf-Witten model and generalized toric code models. Read the published version. Read more
In this paper, we show by computer simulations that a new material, which is a specific combination of the two semiconductors InAs and InSb (both are currently used in experimental setups on Majorana zero modes), has vastly improved properties compared to InAs or InSb alone, making it ideally suited for future devices. Moreover, we Read more
In this paper, published in Physical Review A, we show how to greatly improve success at solving Constraint Satisfaction Problems on a quantum computer by using a learned schedule, instead of the standard linear ramps. The technique actually improves as the problem gets larger and more difficult, allowing classical machines to learn optimizations that Read more
Topological materials can yield quasiparticles that behave in a manner similar to elementary particles that are part of the standard model of particle physics. In this paper, published in Physical Review X, we report on a new class of such quasiparticles—triple point fermions—which represent fermions that have mixed properties of Dirac and Weyl fermions. Read more
In this paper, which was just published in Physical Review B, a quantitative theory for the two-terminal conductance of a proximitized nanowire in the Coulomb blockade regime is developed. This theory allows one to understand and interpret the experimental data from the recent experiment by Charles Marcus’s group at Station Q Copenhagen that demonstrated Read more
The 2016 QRetreat took place on Microsoft’s Redmond campus on April 28 and 29, 2016. QRetreat is an annual meeting of the Station Q Santa Barbara and Station Q Redmond teams. The goals of the meeting are to update each other on the recent research in an informal atmosphere and discuss current projects. This Read more
LIQUi|> is a software architecture and tool suite for quantum computing. It includes a programming language, optimization and scheduling algorithms, and quantum simulators. LIQUi|> can be used to translate a quantum algorithm written in the form of a high-level program into the low-level machine instructions for a quantum device. LIQUi|> is developed by the Read more
In an external magnetic field, the energy of an electron in a two-dimensional system takes discrete values, called Landau levels. At high enough fields, all electrons in a solid can fit in the lowest Landau level. If exactly half of that level is filled with electrons, standard theory predicts that a special fermion liquid Read more
