Related Experiment Video
Updated: May 18, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
A quantum phase transition in a quantum external field: superposing two magnetic phases
Marek M Rams1, Michael Zwolak, Bogdan Damski
1Los Alamos National Laboratory, Theoretical Division, MS B213, Los Alamos, New Mexico 87545, USA.
Scientific Reports
|September 15, 2012
Summary
Researchers created a quantum superposition of Ising chain ground states using a central spin. This method encodes critical point information and exponents in the chain's magnetization.
Area of Science:
- Condensed matter physics
- Quantum magnetism
- Quantum phase transitions
Background:
- Ising models describe magnetic materials and exhibit quantum phase transitions.
- Quantum magnetic fields are crucial for understanding these transitions.
- Superposition states are fundamental in quantum mechanics.
Purpose of the Study:
- To investigate the preparation of quantum superpositions of Ising chain ground states.
- To explore the use of a central spin to emulate quantum magnetic fields.
- To analyze the information encoded in the system's magnetization.
Main Methods:
- Studying an Ising chain undergoing a quantum phase transition.
- Emulating a quantum magnetic field by coupling the chain to a central spin in a superposition.
- Adiabatically driving the system to prepare ground state superpositions.
Main Results:
- Successfully prepared a quantum superposition of any two ground states of the Ising chain.
- Achieved a superposition of ferromagnetic and paramagnetic phases, a novel scenario.
- Demonstrated that magnetization encodes critical point position, universal critical exponents, and ground state fidelity.
Conclusions:
- The central spin emulation technique provides a novel pathway to generate complex quantum states.
- The encoded information in magnetization offers a sensitive probe for critical phenomena.
- This work opens new avenues for studying quantum phase transitions and their characterization.
Related Concept Videos
01:27Magnetic Fields
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
01:23Atomic Nuclei: Nuclear Relaxation Processes
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis. This...
01:03Atomic Nuclei: Nuclear Spin State Overview
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
01:23Magnetic Field due to Moving Charges
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
01:05Atomic Nuclei: Magnetic Resonance
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
01:21Phase Transitions
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...