Imaging the electronic Wigner crystal in one dimension

Abstract

The quantum crystal of electrons, predicted more than eighty years ago by Eugene Wigner, is still one of the most elusive states of matter. Here, we present experiments that observe the one-dimensional Wigner crystal directly, by imaging its charge density in real-space. To measure this fragile state without perturbing it, we developed a new scanning probe platform that utilizes a pristine carbon nanotube as a scanning charge perturbation to image, with minimal invasiveness, the many-body electronic density within another nanotube. The obtained images, of few electrons confined in one-dimension, match those of strongly interacting crystals, with electrons ordered like pearls on a necklace. Comparison to theoretical modeling demonstrates the dominance of Coulomb interactions over kinetic energy and the weakness of exchange interactions. Our experiments provide direct evidence for this long-sought electronic state, and open the way for studying other fragile interacting states by imaging their many-body density in real-space.

Macroscopic manifestation of domain-wall magnetism and magnetoelectric effect in a Néel-type skyrmion host

“…Geometrical or dimensional constraints can promote the formation of new quantum phases which are absent in bulk systems. Prominent examples include metallic surface states in topological insulators 1 , superconducting vortex state below the Kosterlitz-Thouless transition 2 , interface-induced 2D electron gas 3 and superconductivity [4][5][6] , integer and fractional quantum Hall edge states [7][8][9] and Wigner crystals 10,11 in systems with reduced dimensions. Geometrical constraints on the nano-to mesoscale are usually enforced by design in quantum dots, nanowires, thin films, heterostructures, metamaterials, etc.…”

Fast and Ultraclean Approach for Measuring the Transport Properties of Carbon Nanotubes

“…This indicates that FC‐CVD SWCNTs offer the highest electronic quality, compared to other values for CNTs reported in literature. As a result, FC‐CVD SWCNTs can by all means be preferred for thin‐film applications, where mobility still matters, and for quantum sensors, which require less defect sites …”

“…In particular, their low effective mass with the corresponding high carrier velocity, make CNTs and graphene one of the most ideal electron transport systems available . In addition to fundamental transport studies about the novel quantum phenomena, tremendous efforts have been put into the application of CNTs as next‐generation electronic devices . One of the important achievements in CNT‐based electronics has been the fabrication of ultraclean devices .…”

Wigner crystals in two-dimensional transition-metal dichalcogenides: Spin physics and readout

“…Since the earliest indication for quantum Wigner crystals (WCs) obtained from high-magnetic-field transport measurements [2,3], it has proven to be a very demanding task to study WCs, especially in a minimally invasive manner without destroying the crystalline order. Recent experimental work demonstrated non-destructive read-out of the charge distribution of one-dimensional WCs in carbon nanotubes [4]. However, it remains an open challenge to find approaches for the non-invasive detection of WCs in two-dimensional and a broader range of one-dimensional quantum systems.…”