Note on simple and consistent gateset characterization including calibration and decoherence errors

Building high-fidelity quantum computers requires efficient methods for the characterization of gate errors that provide actionable information that may be fed back into engineering efforts. Extraction of realistic error models is also critical to accurate simulation and design of quantum circuits, including those used in quantum error correction. We provide a method for determining the parameters corresponding to decoherence in a model gateset. We demonstrate that this method is robust to SPAM and pulse area errors, and describe a simple and intuitive method for interpreting the quality and precision of the resulting error model

Trumping the First Amendment?

The primary goal of this Essay is to assess whether the relationship between the ideology of Supreme Court Justices and their support for the First Amendment guarantees of speech, press, assembly, and association has declined, such that left-of-center Justices no longer consistently support those guarantees, and right-of-center Justices no longer consistently support their regulation. Utilizing data drawn from the 1953 through 2004 terms of the Court, we show that, in disputes in which only First Amendment claims are at issue, the more liberal the Justice, the higher the likelihood that he or she will vote in favor of litigants alleging an abridgment of their rights. That relationship, however, fails to emerge in disputes in which other values, such as privacy and equality, are also prominently at stake. In these cases, liberal Justices are no more likely than their conservative counterparts to support the First Amendment; indeed, if anything, a reversal of sorts occurs, with conservatives more likely, and liberals less likely, to vote in favor of the speech, press, assembly, or association claim. Taken collectively, these results indicate that commitment to First Amendment values is no longer a lodestar of liberalism. We consider the implications of these findings in light of long-held assumptions of (quantitative) political science work on the Court

Unmarked? Criminal Record Clearing and Employment Outcomes

An estimated one in three American adults has a criminal record. While some records are for serious offenses, most are for arrests or relatively lowlevel misdemeanors. In an era of heightened security concerns, easily available data, and increased criminal background checks, these records act as a substantial barrier to gainful employment and other opportunities. Harvard sociologist Devah Pager describes people with criminal records as “marked” with a negative job credential. In response to this problem, lawyers have launched unmarking programs to help people take advantage of legal record clearing remedies. We studied a random sample of participants in one such program to analyze the impact of the record clearing intervention on employment outcomes. Using methods to control for selection bias and the effects of changes in the economy in our data, we found evidence that: (1) the record clearing intervention boosted participants’ employment rates and average real earnings, and (2) people sought record clearing remedies after a period of suppressed earnings. More research needs to be done to understand the durability of the positive impact and its effects in different local settings and labor markets, but these findings suggest that the record clearing intervention makes a meaningful difference in employment outcomes for people with criminal records. The findings also suggest the importance of early intervention to increase employment opportunities for people with criminal records. Such interventions might include more legal services, but they might also include record clearing by operation of law or another mechanism that does not put the onus of unmarking on the person with a criminal record

Time reversal symmetry breaking in two-dimensional non-equilibrium viscous fluids

We study the rheological signatures of departure from equilibrium in two-dimensional viscous fluids with and without internal spin. Under the assumption of isotropy, we provide the most general linear constitutive relations for stress and couple stress in terms of the velocity and spin fields. Invoking Onsager's regression hypothesis for fluctuations about steady states, we derive the Green-Kubo formulae relating the transport coefficients to time correlation functions of the fluctuating stress. In doing so, we verify the claim that one of the non-equilibrium transport coefficients, the odd-viscosity, requires time reversal symmetry breaking in the case of systems without internal spin. However, the Green-Kubo relations for systems with internal spin also show that there is a possibility for non-vanishing odd viscosity even when time reversal symmetry is preserved. Furthermore, we find that breakdown of equipartition in non-equilibrium steady states results in the decoupling of the two rotational viscosities relating the vorticity and the internal spin

Ideological Drift Among Supreme Court Justices: Who, When, and How Important?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116215/1/nw07.pd

Statistical Mechanics of Transport Processes in Active Fluids II: Equations of Hydrodynamics for Active Brownian Particles

We perform a coarse-graining analysis of the paradigmatic active matter model, Active Brownian Particles, yielding a continuum description in terms of balance laws for mass, linear and angular momentum, and energy. The derivation of the balance of linear momentum reveals that the active force manifests itself directly as a continuum-level body force proportional to an order parameter-like director field, which therefore requires its own evolution equation to complete the continuum description of the system. We derive this equation, demonstrating in the process that bulk currents may be sustained in homogeneous systems only in the presence of inter-particle aligning interactions. Further, we perform a second coarse-graining of the balance of linear momentum and derive the expression for active or swim pressure in the case of mechanical equilibrium.Comment: 9 pages, 3 appendices with derivation