Synopsis: Grounding the Hubbard Model

Researchers propose a step-by-step quantum recipe to find the ground state of models of strongly interacting electrons.

Quantum computing evokes the idea of a general-purpose quantum desktop machine. But a more realistic application may lie in quantum simulation. This involves using one quantum system to simulate another, providing a way to explore problems intractable with classical computers. Dave Wecker from Microsoft Research, Washington, and co-workers propose a step-by-step recipe to determine the otherwise difficult to calculate ground state of models of strongly interacting electrons in solids using quantum simulation. When applied to a real simulator, the recipe may help advance our understanding of strongly correlated materials such as high-temperature superconductors.

The researchers focus their study on the Hubbard model—the simplest model of interacting electrons in a lattice. The model has long been used to describe strongly correlated phenomena in condensed-matter physics. Their recipe, which maps the model’s states of interacting electrons onto the states of a quantum simulator based on interacting qubits, comprises three main steps. First, starting from different initial states, corresponding to different phases of matter, the simulator is smoothly (adiabatically) taken to an approximate ground state. Second, it performs an algorithm to find the true ground state from this approximate state. Third, measurements are made on the simulator to extract information about the ground state, such as particle-particle correlations. This information is used to determine the nature of the ground state. Crucially, the authors describe the complete set of qubits and logic gates needed to implement their approach.

This research is published in Physical Review A.

­–Ana Lopes


Announcements

More Announcements »

Subject Areas

Quantum PhysicsCondensed Matter Physics

Previous Synopsis

Biological Physics

Termite Skyscrapers

Read More »

Next Synopsis

Graphene

Graphene Majoranas

Read More »

Related Articles

Synopsis: Tickled by a Wigner Crystal
Mesoscopics

Synopsis: Tickled by a Wigner Crystal

The lattice symmetry of a quantum Wigner crystal is deduced from its effect on quantized states in a nearby sheet of electrons. Read More »

Viewpoint: Ionization Delays That Stand Out
Optics

Viewpoint: Ionization Delays That Stand Out

Attosecond-resolution experiments have determined the delay in an electron’s emission from a molecule after being ionized with light. Read More »

Synopsis: World of Weyl Craft
Condensed Matter Physics

Synopsis: World of Weyl Craft

Researchers provide new evidence for the existence of type-II Weyl semimetals, which would be both conducting and insulating in different spatial directions.  Read More »

More Articles