scholarly journals Time-Rescaling of Dirac Dynamics: Shortcuts to Adiabaticity in Ion Traps and Weyl Semimetals

Entropy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 81
Author(s):  
Agniva Roychowdhury ◽  
Sebastian Deffner
Keyword(s):  
Time Dependence ◽  
Unitary Transformation ◽  
Ion Traps ◽  
Time Frame ◽  
Effective Potentials ◽  
Shortcuts To Adiabaticity ◽  
Weyl Semimetals ◽  
Adiabatic Dynamics

Only very recently, rescaling time has been recognized as a way to achieve adiabatic dynamics in fast processes. The advantage of time-rescaling over other shortcuts to adiabaticity is that it does not depend on the eigenspectrum and eigenstates of the Hamiltonian. However, time-rescaling requires that the original dynamics are adiabatic, and in the rescaled time frame, the Hamiltonian exhibits non-trivial time-dependence. In this work, we show how time-rescaling can be applied to Dirac dynamics, and we show that all time-dependence can be absorbed into the effective potentials through a judiciously chosen unitary transformation. This is demonstrated for two experimentally relevant scenarios, namely for ion traps and adiabatic creation of Weyl points.

scholarly journals Hamiltonian transformability, fast adiabatic dynamics and hidden adiabaticity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lian-Ao Wu ◽  
Dvira Segal
Keyword(s):  
Hilbert Space ◽  
Existence Theorem ◽  
Quantum Computation ◽  
Unitary Transformation ◽  
Adiabatic Quantum Computation ◽  
Promising Application ◽  
Adiabatic Regime ◽  
Adiabatic Dynamics

AbstractWe prove the existence of a unitary transformation that enables two arbitrarily given Hamiltonians in the same Hilbert space to be transformed into one another. The result is straightforward yet, for example, it lays the foundation to implementing or mimicking dynamics with the most controllable Hamiltonian. As a promising application, this existence theorem allows for a rapidly evolving realization of adiabatic quantum computation by transforming a Hamiltonian where dynamics is in the adiabatic regime into a rapidly evolving one. We illustrate the theorem with examples.

scholarly journals DIAMAGNETIC INEQUALITIES FOR SYSTEMS OF NONRELATIVISTIC PARTICLES WITH A QUANTIZED FIELD

1996 ◽  
Vol 08 (02) ◽  
pp. 185-203 ◽  
Author(s):  
FUMIO HIROSHIMA
Keyword(s):  
Quantum Electrodynamics ◽  
Unitary Transformation ◽  
Product Formula ◽  
Nelson Model ◽  
Trotter Product Formula ◽  
Gauge Transformations ◽  
Effective Potentials ◽  
Unitary Transformations ◽  
Quantized Field ◽  
Bogoliubov Transformations

By unitary transformations (gauge transformations, the Bogoliubov transformations) and the strong Trotter product formula, diamagnetic inequalities for the Pauli-Fierz model of quantum electrodynamics (QED) and the Nelson model are derived. In the Nelson model, the unitary transformation defines effective potentials. Moreover, the infimum of the spectrum of Hamiltonians for these models are estimated and some generalized Kato’s inequalities are obtained.

The O–C diagrams of minor planets − a new approach to modelling the rotation

1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss
Keyword(s):  
Error Analysis ◽  
Time Dependence ◽  
Theoretical Work ◽  
Minor Planet ◽  
Minor Planets ◽  
New Approach ◽  
Preliminary Results ◽  
Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

Effective potentials in glassy systems

1998 ◽  
Vol 77 (2) ◽  
pp. 239-243
Author(s):  
S. Franz, G. Parisi
Keyword(s):  
Effective Potentials ◽  
Glassy Systems

Effects of Momentary Affect on Satisfaction Judgments

2020 ◽  
Vol 41 (2) ◽  
pp. 61-67
Author(s):  
Marko Tončić ◽  
Petra Anić
Keyword(s):  
Linear Models ◽  
Time Frame ◽  
Hierarchical Linear Models ◽  
Curvilinear Relationship ◽  
Positive And Negative Affect ◽  
Transient Events ◽  
Time Frames ◽  
Events Data ◽  
Level Satisfaction ◽  
Source Of Information

Abstract. This study aims to examine the effect of affect on satisfaction, both at the between- and the within-person level for momentary assessments. Affect is regarded as an important source of information for life satisfaction judgments. This affective effect on satisfaction is well established at the dispositional level, while at the within-person level it is heavily under-researched. This is true especially for momentary assessments. In this experience sampling study both mood and satisfaction scales were administered five times a day for 7 days via hand-held devices ( N = 74 with 2,122 assessments). Several hierarchical linear models were fitted to the data. Even though the amount of between-person variance was relatively low, both positive and negative affect had substantial effects on momentary satisfaction on the between- and the within-person level as well. The within-person effects of affect on satisfaction appear to be more pronounced than the between-person ones. At the momentary level, the amount of between-person variance is lower than in studies with longer time-frames. The affect-related effects on satisfaction possibly have a curvilinear relationship with the time-frame used, increasing in intensity up to a point and then decreasing again. Such a relationship suggests that, at the momentary level, satisfaction might behave in a more stochastic manner, allowing for transient events/data which are not necessarily affect-related to affect it.

The effect of request time frame on compliance

2004 ◽  
Author(s):  
Sabrina Kelly ◽  
Leandre Fabrigar ◽  
Tara MacDonald
Keyword(s):  
Time Frame

Time Frame Orientation scale

2011 ◽  
Author(s):  
Samuel T. Hunter ◽  
Liliya Cushenbery ◽  
Christian Thoroughgood ◽  
Johanna E. Johson ◽  
Gina Scott Ligon
Keyword(s):  
Time Frame ◽  
Orientation Scale ◽  
Frame Orientation

Influence of the hyperfine structure on the time-dependence of Mössbauer transmission

1985 ◽  
Vol 46 (8) ◽  
pp. 1387-1393 ◽  
Author(s):  
D.L. Balabanski ◽  
E.I. Vapirev ◽  
P.S. Kamenov
Keyword(s):  
Time Dependence ◽  
Hyperfine Structure

Time Dependence of Whole Blood Aggregation in Response to Platelet Activating Factor (PAF)

1988 ◽  
Vol 59 (02) ◽  
pp. 162-163 ◽  
Author(s):  
R R Taylor ◽  
J Strophair ◽  
M Sturm ◽  
R Vandongen ◽  
L J Beilin
Keyword(s):  
Time Dependence ◽  
Whole Blood ◽  
Platelet Rich Plasma ◽  
Platelet Activating Factor ◽  
Sampling Time ◽  
Blood Sampling ◽  
Impedance Aggregometry

SummaryThe aggregation/adhesion response to platelet activating factor (PAF) was studied in diluted whole blood by impedance aggregometry. The extent of aggregation varied directly with the interval between blood sampling and aggregation measurement over the first 30 minutes from sampling, then remained stable for the next 60 minutes of observation. This is an effect opposite to that described for aggregation to PAF in platelet rich plasma which, however, cannot be studied soon after sampling. Time dependence of aggregation is important and comparative measurements should be made during the period of stable aggregability.

Colchicine Uptake and Binding by Human Platelets

1975 ◽  
Vol 34 (03) ◽  
pp. 780-794 ◽  
Author(s):  
Dianne M Kenney ◽  
Francis C Chao ◽  
James L Tullis ◽  
Gail S Conneely
Keyword(s):  
Time Dependence ◽  
Incubation Period ◽  
Binding Sites ◽  
Silicone Oil ◽  
Cold Treatment ◽  
Human Platelets ◽  
Temperature Dependent

SummaryThe uptake and binding of antimitotic alkaloid colchicine has been demonstrated in washed preparations of human platelets. A silicone oil technique was adapted so that both uptake and binding of 14C-colchicine were examined in the same platelet preparations. The time dependence and amount of colchicine taken up and bound by different platelet preparations during a 90 to 120 min incubation period were highly reproducible. Both colchicine uptake and binding by intact platelets, and colchicine binding by preparations of lysed platelets were specific and temperature dependent. Colchicine uptake was slowly reversible. Magnesium and GTP enhanced colchicine binding by lysed platelet preparations but calcium decreased binding.Exposure of platelets to either cold (4° C) or to thrombin, which disrupt platelet microtubules, produced significant increases in colchicine uptake and binding. The thrombin effect was maximal at 37° C and resulted in a greater increase in uptake and binding than that produced by either cold treatment alone or, by cold treatment followed by incubation with thrombin at 37° C. The amount of increase in uptake and binding produced by thrombin was independent of both thrombin (1–5 Units/109 platelets) and colchicine concentrations (1–50 × 10−6M).It is postulated that thrombin may initiate the formation, or make available, colchicine binding sites (microtubule subunits) within platelets.

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