23,265 research outputs found
New York\u27s Juvenile Offender Law: An Overview and Analysis
In response to the public outrage over the light sentencing of some of New York City\u27s juvenile offenders who had committed heinous crimes, the legislature enacted the Crime Package Bill which made revisions to the entire justice system. The result was that New York was provided with some of the harshest juvenile justice systems in the country. This Article argues that the system is both ineffective and inefficient. First, the Article examines the historical development of the juvenile system, then the more recent reforms of the system, and finally the problems created by the Crime Package Bill
Autonomous Ticking Clocks from Axiomatic Principles
There are many different types of time keeping devices. We use the phrase
ticking clock to describe those which -- simply put -- "tick" at approximately
regular intervals. Various important results have been derived for ticking
clocks, and more are in the pipeline. It is thus important to understand the
underlying models on which these results are founded. The aim of this paper is
to introduce a new ticking clock model from axiomatic principles that overcomes
concerns in the community about the physicality of the assumptions made in
previous models. The ticking clock model in [arXiv:1806.00491] achieves high
accuracy, yet lacks the autonomy of the less accurate model in
[10.1103/PhysRevX.7.031022]. Importantly, the model we introduce here achieves
the best of both models: it retains the autonomy of [10.1103/PhysRevX.7.031022]
while allowing for the high accuracies of [arXiv:1806.00491]. What is more,
[10.1103/PhysRevX.7.031022] is revealed to be a special case of the new ticking
clock model.Comment: 14 + 14 page
Experimental Issues for Precision Electroweak Physics at a High-Luminosity Z Factory
We discuss the ultimate precision for ALR, and therefore for the weak mixing
angle, at a high-luminosity Linear Collider. Drawing on our experience at the
SLC, and considering various machine parameter sets for the NLC and for TESLA,
it emerges that a compromise between peak luminosity and precision will be a
likely outcome. This arises due to the severe requirements on the uncertainty
in the luminosity weighted collision energy (Ecm). We consider the cases with
and without a polarized positron beam.Comment: Submitted to LCWS2000 (Linear Collider Workshop 20000), Fermilab,
10-24-200
Continuous groups of transversal gates for quantum error correcting codes from finite clock reference frames
Following the introduction of the task of reference frame error correction,
we show how, by using reference frame alignment with clocks, one can add a
continuous Abelian group of transversal logical gates to any error-correcting
code. With this we further explore a way of circumventing the no-go theorem of
Eastin and Knill, which states that if local errors are correctable, the group
of transversal gates must be of finite order. We are able to do this by
introducing a small error on the decoding procedure that decreases with the
dimension of the frames used. Furthermore, we show that there is a direct
relationship between how small this error can be and how accurate quantum
clocks can be: the more accurate the clock, the smaller the error; and the
no-go theorem would be violated if time could be measured perfectly in quantum
mechanics. The asymptotic scaling of the error is studied under a number of
scenarios of reference frames and error models. The scheme is also extended to
errors at unknown locations, and we show how to achieve this by simple majority
voting related error correction schemes on the reference frames. In the
Outlook, we discuss our results in relation to the AdS/CFT correspondence and
the Page-Wooters mechanism.Comment: 10+35 pages. Also see related work uploaded to the arXiv on the same
day; arXiv:1902.0771
Dynamical error bounds for continuum discretisation via Gauss quadrature rules, -- a Lieb-Robinson bound approach
Instances of discrete quantum systems coupled to a continuum of oscillators
are ubiquitous in physics. Often the continua are approximated by a discrete
set of modes. We derive analytical error bounds on expectation values of system
observables that have been time evolved under such discretised Hamiltonians.
These bounds take on the form of a function of time and the number of discrete
modes, where the discrete modes are chosen according to Gauss quadrature rules.
The derivation makes use of tools from the field of Lieb-Robinson bounds and
the theory of orthonormal polynominals.Comment: 12 pages + 14 pages of proofs and appendices, Journal of Mathematical
Physics, Vol.57, Issue 2 (2016)
http://scitation.aip.org/content/aip/journal/jmp/57/2/10.1063/1.494043
Universal quantum modifications to general relativistic time dilation in delocalised clocks
The theory of relativity associates a proper time with each moving object via
its world line. In quantum theory however, such well-defined trajectories are
forbidden. After introducing a general characterisation of quantum clocks, we
demonstrate that, in the weak-field, low-velocity limit, all "good" quantum
clocks experience time dilation as dictated by general relativity when their
state of motion is classical (i.e. Gaussian). For nonclassical states of
motion, on the other hand, we find that quantum interference effects may give
rise to a significant discrepancy between the proper time and the time measured
by the clock. The universality of this discrepancy implies that it is not
simply a systematic error, but rather a quantum modification to the proper time
itself. We also show how the clock's delocalisation leads to a larger
uncertainty in the time it measures -- a consequence of the unavoidable
entanglement between the clock time and its center-of-mass degrees of freedom.
We demonstrate how this lost precision can be recovered by performing a
measurement of the clock's state of motion alongside its time reading.Comment: 7 + 10 pages. V3: accepted versio
The maximum efficiency of nano heat engines depends on more than temperature
Sadi Carnot's theorem regarding the maximum efficiency of heat engines is
considered to be of fundamental importance in thermodynamics. This theorem
famously states that the maximum efficiency depends only on the temperature of
the heat baths used by the engine, but not on the specific structure of baths.
Here, we show that when the heat baths are finite in size, and when the engine
operates in the quantum nanoregime, a revision to this statement is required.
We show that one may still achieve the Carnot efficiency, when certain
conditions on the bath structure are satisfied; however if that is not the
case, then the maximum achievable efficiency can reduce to a value which is
strictly less than Carnot. We derive the maximum efficiency for the case when
one of the baths is composed of qubits. Furthermore, we show that the maximum
efficiency is determined by either the standard second law of thermodynamics,
analogously to the macroscopic case, or by the non increase of the max relative
entropy, which is a quantity previously associated with the single shot regime
in many quantum protocols. This relative entropic quantity emerges as a
consequence of additional constraints, called generalized free energies, that
govern thermodynamical transitions in the nanoregime. Our findings imply that
in order to maximize efficiency, further considerations in choosing bath
Hamiltonians should be made, when explicitly constructing quantum heat engines
in the future. This understanding of thermodynamics has implications for
nanoscale engineering aiming to construct small thermal machines.Comment: Main text 14 pages. Appendix 60 pages. Accepted in Journal Quantu
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