Physics Letters B 768 (2017) 288–291
Contents lists available at ScienceDirect
Physics Letters B
www.elsevier.com/locate/physletb
Note on the butterfly effect in holographic superconductor models
Yi Ling
a,c,d
, Peng Liu
a
, Jian-Pin Wu
b,c,∗
a
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
b
Institute of Gravitation and Cosmology, Department of Physics, School of Mathematics and Physics, Bohai University, Jinzhou 121013, China
c
Shanghai Key Laboratory of High Temperature Superconductors, Shanghai 200444, China
d
School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
a r t i c l e i n f o a b s t r a c t
Article history:
Received
3 December 2016
Received
in revised form 13 February 2017
Accepted
6 March 2017
Available
online 9 March 2017
Editor:
N. Lambert
In this note we remark that the butterfly effect can be used to diagnose the phase transition of
superconductivity in a holographic framework. Specifically, we compute the butterfly velocity in a
charged black hole background as well as anisotropic backgrounds with Q-lattice structure. In both cases
we find its derivative to the temperature is discontinuous at critical points. We also propose that the
butterfly velocity can signalize the occurrence of thermal phase transition in general holographic models.
© 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP
3
.
1. Introduction
Recently quantum butterfly effect has been becoming a hot
spot of research which links the gauge/gravity duality to quan-
tum
many-body theory and quantum information theory [1–24].
Diagnosed by the out-of-time-order correlation (OTOC) functions,
the butterfly effect describes the information scrambling over a
quantum chaotic system. On gravity side, the butterfly effect is
described by a shock wave geometry on the horizon that can be
induced by an infalling particle which is exponentially accelerated.
The butterfly effect ubiquitously exists in holographic theories due
to its sole dependence on the near horizon data of the gravita-
tional
bulk theory. In particular, the Lyapunov exponent λ
L
is al-
ways
characterized by the Hawking temperature of the black hole
as λ
L
= 2πk
B
T , while the butterfly velocity is completely deter-
mined
by the horizon geometry [14,16,18]. Moreover, a bound on
chaos is proposed as λ
L
2πk
B
T and the saturation of this bound
is viewed as the criterion for a quantum chaotic system to have a
classical gravity dual description [9]. Stimulated by above investi-
gation
in holographic approach, many physicists in condensed mat-
ter
as well as quantum information community have made great
efforts in the measurement of the OTOC in laboratory [13,21–23].
The related progress is supposed to provide more practical tools to
test the proposals in holographic theories, and in turn push for-
ward
the investigation on butterfly effects in quantum many-body
systems.
*
Corresponding author.
E-mail
addresses: lingy@ihep.ac.cn (Y. Ling), liup51@ihep.ac.cn (P. Liu),
jianpinwu@mail.bnu.edu.cn (J.-P. Wu).
In recent paper [18] we have investigated the butterfly effect in
holographic models which exhibit metal-insulator transition (MIT)
and found that the butterfly velocity v
B
can diagnose quantum
phase transitions (QPT). The key point on this is that the occur-
rence
of QPT usually involves the RG flows from UV to different IR
fixed points [25]. On the other hand, the butterfly velocity v
B
de-
pends
on the IR geometry solely. Therefore, the change of IR fixed
points may be reflected by the distinct behavior of v
B
. In this note
we intend to argue that the butterfly effect can exhibit attractive
behavior during the course of thermal phase transition as well.
This extension is natural, since based on Landau theory the oc-
currence
of thermal phase transition is always accompanied by a
symmetry breaking characterized by some order parameter. While
in the context of holography, the spontaneous breaking of sym-
metry
is usually a reflection of the instability of the background
in bulk, signalized by the appearance of black hole hair which
is supposed to deform the horizon, namely IR geometry strongly.
Therefore, to provide evidence to support above argument we will
investigate the temperature behavior of the butterfly velocity in
holographic superconductor models. Specifically we will demon-
strate
that the derivative of v
B
to the temperature is discontinuous
at critical points of phase transition.
We
organize this paper as follows. In next section we will first
consider the butterfly effect in the simplest holographic model
with superconductivity which is constructed over a charged black
hole. Then we turn to study this effect over more complicated
backgrounds with lattice structure in subsection 2.3. A brief dis-
cussion
about possible extensions and experimental prospects will
be presented in the end of this note.
http://dx.doi.org/10.1016/j.physletb.2017.03.010
0370-2693/
© 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by
SCOAP
3
.