Temperature can enhance coherent oscillations at ... - Robert S Whitney
Spin-interaction + symmetry of cluster. =â ground-state = LARGE S. Spin-states relax at temperatures > few Kelvin. Two possible scenarios for this;. (a) nuclear ...
Laboratoire de Physique et Modelisation ´ des Milieux Condenses ´ Univ. J. Fourier & CNRS, Grenoble, France
Temperature can enhance coherent oscillations at a Landau-Zener transition Robert S. Whitney1,2 , Maxim Clusel2,3 , Timothy Ziman1,2 1. LPMMC, Univ. J. Fourier & CNRS, Grenoble 2. Institut Laue Langevin, Grenoble 3. Laboratoire des Collo¨ıdes, Verres et Nanomat´ eriaux, Univ. Montpellier II & CNRS
Phys. Rev. Lett. 107, 210402 (2011) GDR Physique Quantique Mesoscopique, ´ Decembre ´ 2011
[1] SUMMARY Typically: coupling to environment causes decoherence
...BUT we show that an environment can also enhance coherent oscillations. ⇒ coherent osc. grow strongly with increasing temperature
Origin in Lamb-shift ⇒ we call effect
\Lamb-assisted oherent os illations"
♣ New probe for high-frequency environments in
qubits, mole ular magnets, et .
[2] MODEL instantaneous eigenenergies
SYSTEM
e.g. bath of bosons temperature = T
∆
time, t
adia
bati
System Hamiltonian:
LARGE ENVIRONMENT
c
Landau-Zener
OR CLASSICAL NOISE
HtLZ = − 21 νt σz + ∆ σx
Full Hamiltonian — system+environ. Htsys&env = HtLZ − 12 σz X + Henv with X operator acting weakly on a huge number of environ. modes, Henv .
[3] RESULTS (b) Lamb shift and no decoherence
(a) Decoherence and no Lamb-shift =⇒ suppresses oscillations
High-freq. environment
Markovian environ. (white-noise) sx (t )
=⇒ ENHANCES oscillations
1
sx (t )
dashed: no coupling to env. solid: coupled to env.
1
dashed: no coupling to env. solid: coupled to env. 1 2
1 2
ν 1/2 t -8
-4
4
sy (t ) - 12
sz (t ) -1
8
A
12
11111111111111111111 00000000000000000000 00000000000000000000 11111111111111111111 A vs. ξzR 00000000000000000000 11111111111111111111 æ 00000000000000000000 11111111111111111111 æ æ 00000000000000000000 11111111111111111111 0.1 ∆/ν 1/2= 2.0 æ 00000000000000000000 11111111111111111111 æ à æ 00000000000000000000 11111111111111111111 à æ 00000000000000000000 11111111111111111111 à à 00000000000000000000 11111111111111111111 à 00000000000000000000 11111111111111111111 à 2.4 0.01ì à 00000000000000000000 11111111111111111111 ì 00000000000000000000 11111111111111111111 ì ì 00000000000000000000 11111111111111111111 ì 00000000000000000000 11111111111111111111 ì 2.8 ì 00000000000000000000 11111111111111111111 ò ò 0.001 00000000000000000000 11111111111111111111 ò 00000000000000000000 11111111111111111111 ò 00000000000000000000 11111111111111111111 ò ò 3.2ò 00000000000000000000 11111111111111111111 00000000000000000000 11111111111111111111 00000000000000000000 11111111111111111111 00000000000000000000 11111111111111111111 0.05 0.1 0.15 00000000000000000000 11111111111111111111 00000000000000000000 11111111111111111111 00000000000000000000 11111111111111111111
ν 1/2 t -8
-4
sy (t )
sz (t )
4
8
12
A 000000000000000000000 111111111111111111111 A vs. γ 000000000000000000000 111111111111111111111 0.5 ∆/ν 1/2æ= 2.0 æ 111111111111111111111 æ - 12 000000000000000000000 æ 000000000000000000000 111111111111111111111 æ æ æ 000000000000000000000 111111111111111111111 2.4à 000000000000000000000 111111111111111111111 à à 0.1 000000000000000000000 111111111111111111111 à à 000000000000000000000 111111111111111111111 à 2.8ì à 000000000000000000000 111111111111111111111 ì 000000000000000000000 111111111111111111111 ì 000000000000000000000 111111111111111111111 ì ì 000000000000000000000 111111111111111111111 3.2ò ì -1 111111111111111111111 000000000000000000000 0.01ì ò 000000000000000000000 111111111111111111111 ò 000000000000000000000 111111111111111111111 ò 000000000000000000000 111111111111111111111 ò 000000000000000000000 111111111111111111111 ò 000000000000000000000 111111111111111111111 ò 000000000000000000000 111111111111111111111 0.001 000000000000000000000 111111111111111111111 000000000000000000000 111111111111111111111 000000000000000000000 111111111111111111111 0.1 0.2 0.3 000000000000000000000 111111111111111111111 000000000000000000000 111111111111111111111 000000000000000000000 111111111111111111111
[4] From LAMB-SHIFT to TEMPERATURE-DEPENDENCE “Lamb-shift = level-repulsion” Competition between: (1) Lamb-shift ⇐ high-freq. modes reduces system gap while low-freq. modes increase gap
(2) decoherence ⇐ env. modes in resonance with system gap
Dec 10, 2016 - Either a temperature gradient across a material can produce electricity ... Wasted heat yields a huge loss of energy in many domains. This is the ...
Why does random matrix theory work so well ? Why doesn't random matrix theory work ? Ehrenfest time, t. E. , a measure of classical-ness. Random matrix.
THEORY µHAND-WAVING PICTURE path1 path2. Andreev reflection. Phaseâshift fluctuates from path to path Ï Î´Ï e h e h. AVERAGE: e µh h µe Ñв. ¢. ¾¯ Ñ Â·.
Classical particles: No noise in current ...and classical limit of quantum? Random matrix theory (RMT). â ânoise in classical limitâ. NEW REGIME in classical limit ...
time z. B mem Ï. 1/Ïmem area = Î. Noise spectrum. 000000000. 000000000. 000000000. 000000000 .... + perturbation theory on new H (equiv to NIBA). Terms missed by RG; in x ... Go from strongly time-dependent problem to (almost) ...
the last 20 years in West Greenland. We present results on the Jakobshavn tide water glacier flow, motion of icebergs and tide extracted from a set of of over 300 ...
your way. So I'11 but I. --. -- know,. I'll think of you every step of the. Way-. And. Tempo= 60. Chats- ... ಮà³à²¨ - ಮà³. (. = will al-ways love you.. ? 11. (with pdat). Dmaj? A(2). : I will_ ai-ways love you. .... I hope life treats you kind.
1 interpolation of the original image to smooth JPEG compression boundaries and ... Matlab's imresize() bilinear interpolation (weighted average of pixels.
Jul 14, 2014 - Nonuniformity of a planar polarizer for spin-transfer-induced vortex oscillations at .... magnetic field, and also set the vortex chirality through the.
Nov 17, 2013 - data and for the outcome measures are described in the Supplementary ... Table 1. Characteristics of the Modified Intention-to-Treat Population before Randomization.* ..... the basis of these results, decisions about which.
to move synchronously with the moving grating. ... move from the first spot to the second as commonly ..... at a suitable SOA (say 150 to 300 msec), then one.
are a linear and coherent superposition of the exciton and photon states, called cavity polaritons. ... ened resulting in very large exciton binding energies of a.
Abstract. MOSFET matching parameters are measured at low temperature (77 - 130 K) for simulation of mixed analog-digital circuits used in cooled infrared ...
Feb 12, 1998 - ozone which has been observed at middle latitudes over the past decade1. D ... 1. Scientific Assessment of Ozone Depletion: 1994 (Rep. No.
Sep 15, 2018 - compression experiments performed at very high stresses has been attributed to the ... mobility of either partial or perfect dislocations [10e12]. In addi- tion, recent works ... revisit the paradigm of low temperature plasticity in si
Oct 3, 2010 - for George Abecassis achieving third place in the 1955 Redex Trophy race at Castlecombe. He continued to race with Abecassis in an HWM for ...
ELF oscillations associated with electron beam injections from the space shuttle. Abstract ELF oscillations (f< 500 Hz) were observed during the electron beam ...
Oct 28, 2013 - services, licences, property rights and habitat banking. 2. .... Habitat banking aims at conserving the ... community at risk purposefully and in.
