scholarly journals Observation of a quantum phase transition in the quantum Rabi model with a single trapped ion

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
M.-L. Cai ◽  
Z.-D. Liu ◽  
W.-D. Zhao ◽  
Y.-K. Wu ◽  
Q.-X. Mei ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermodynamic Limit ◽  
Quantum Phase Transitions ◽  
Paul Trap ◽  
Single Mode ◽  
Quantum Phase ◽  
Controlled Study ◽  
Many Body ◽  
Rabi Model ◽  
Many Body Systems

AbstractQuantum phase transitions (QPTs) are usually associated with many-body systems in the thermodynamic limit when their ground states show abrupt changes at zero temperature with variation of a parameter in the Hamiltonian. Recently it has been realized that a QPT can also occur in a system composed of only a two-level atom and a single-mode bosonic field, described by the quantum Rabi model (QRM). Here we report an experimental demonstration of a QPT in the QRM using a 171Yb+ ion in a Paul trap. We measure the spin-up state population and the average phonon number of the ion as two order parameters and observe clear evidence of the phase transition via adiabatic tuning of the coupling between the ion and its spatial motion. An experimental probe of the phase transition in a fundamental quantum optics model without imposing the thermodynamic limit opens up a window for controlled study of QPTs and quantum critical phenomena.

scholarly journals GEOMETRIC PHASES AND QUANTUM PHASE TRANSITIONS

2008 ◽  
Vol 22 (06) ◽  
pp. 561-581 ◽  
Author(s):  
SHI-LIANG ZHU
Keyword(s):  
Phase Transitions ◽  
Geometric Phase ◽  
Quantum Phase Transitions ◽  
Condensed Matter ◽  
Quantum Phase ◽  
Many Body ◽  
Scientific Communities ◽  
Geometric Phases ◽  
Many Body Systems ◽  
The Many

Quantum phase transition is one of the main interests in the field of condensed matter physics, while geometric phase is a fundamental concept and has attracted considerable interest in the field of quantum mechanics. However, no relevant relation was recognized before recent work. In this paper, we present a review of the connection recently established between these two interesting fields: investigations in the geometric phase of the many-body systems have revealed the so-called "criticality of geometric phase", in which the geometric phase associated with the many-body ground state exhibits universality, or scaling behavior in the vicinity of the critical point. In addition, we address the recent advances on the connection of some other geometric quantities and quantum phase transitions. The closed relation recently recognized between quantum phase transitions and some of the geometric quantities may open attractive avenues and fruitful dialogue between different scientific communities.

scholarly journals Diagonal entropy in many-body systems: Volume effect and quantum phase transitions

2020 ◽  
Vol 384 (16) ◽  
pp. 126333
Author(s):  
Zhengan Wang ◽  
Zheng-Hang Sun ◽  
Yu Zeng ◽  
Haifeng Lang ◽  
Qiantan Hong ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Quantum Phase Transitions ◽  
Volume Effect ◽  
Quantum Phase ◽  
Many Body ◽  
Many Body Systems

scholarly journals Classical and Quantum Signatures of Quantum Phase Transitions in a (Pseudo) Relativistic Many-Body System

2020 ◽  
Vol 5 (2) ◽  
pp. 26
Author(s):  
Maximilian Nitsch ◽  
Benjamin Geiger ◽  
Klaus Richter ◽  
Juan-Diego Urbina
Keyword(s):  
Phase Transition ◽  
Quantum Phase Transition ◽  
Quantum Phase Transitions ◽  
Mean Field ◽  
Finite Size ◽  
Quantum Phase ◽  
Effective Model ◽  
Field Analysis ◽  
Many Body ◽  
Linear Dispersion

We identify a (pseudo) relativistic spin-dependent analogue of the celebrated quantum phase transition driven by the formation of a bright soliton in attractive one-dimensional bosonic gases. In this new scenario, due to the simultaneous existence of the linear dispersion and the bosonic nature of the system, special care must be taken with the choice of energy region where the transition takes place. Still, due to a crucial adiabatic separation of scales, and identified through extensive numerical diagonalization, a suitable effective model describing the transition is found. The corresponding mean-field analysis based on this effective model provides accurate predictions for the location of the quantum phase transition when compared against extensive numerical simulations. Furthermore, we numerically investigate the dynamical exponents characterizing the approach from its finite-size precursors to the sharp quantum phase transition in the thermodynamic limit.

scholarly journals Novel quantum phase transition from bounded to extensive entanglement

2017 ◽  
Vol 114 (20) ◽  
pp. 5142-5146 ◽  
Author(s):  
Zhao Zhang ◽  
Amr Ahmadain ◽  
Israel Klich
Keyword(s):  
Phase Transition ◽  
Quantum Phase Transition ◽  
Ground States ◽  
Quantum Correlations ◽  
Quantum Phase ◽  
Continuous Family ◽  
Many Body ◽  
Many Body Systems ◽  
Special Circumstances ◽  
Area Law

The nature of entanglement in many-body systems is a focus of intense research with the observation that entanglement holds interesting information about quantum correlations in large systems and their relation to phase transitions. In particular, it is well known that although generic, many-body states have large, extensive entropy, ground states of reasonable local Hamiltonians carry much smaller entropy, often associated with the boundary length through the so-called area law. Here we introduce a continuous family of frustration-free Hamiltonians with exactly solvable ground states and uncover a remarkable quantum phase transition whereby the entanglement scaling changes from area law into extensively large entropy. This transition shows that entanglement in many-body systems may be enhanced under special circumstances with a potential for generating “useful” entanglement for the purpose of quantum computing and that the full implications of locality and its restrictions on possible ground states may hold further surprises.

Sign in / Sign up

Export Citation Format

Share Document