Towards Utilizing Scanning Gate Microscopy as a High-Resolution Probe of Valley Splitting in Si/SiGe Heterostructures

• URL: http://arxiv.org/abs/2405.03596v1
• Date: Mon, 6 May 2024 16:05:12 GMT
• Title: Towards Utilizing Scanning Gate Microscopy as a High-Resolution Probe of Valley Splitting in Si/SiGe Heterostructures
• Authors: Efe Cakar, H. Ekmel Ercan, Gordian Fuchs, Artem O. Denisov, Christopher R. Anderson, Mark F. Gyure, Jason R. Petta,
• Abstract summary: We show that a tip-induced quantum dot formed near source and drain electrodes can be adiabatically moved to a region far from the gate electrodes. We argue that by spatially translating the tip-induced dot across a defect in the Si/SiGe interface, changes in valley splitting can be detected.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: A detailed understanding of the material properties that affect the splitting between the two low-lying valley states in Si/SiGe heterostructures will be increasingly important as the number of spin qubits is increased. Scanning gate microscopy has been proposed as a method to measure the spatial variation of the valley splitting as a tip-induced dot is moved around in the plane of the Si quantum well. We develop a simulation using an electrostatic model of the scanning gate microscope tip and the overlapping gate structure combined with an approximate solution to the three-dimensional Schr\"odinger-Poisson equation in the device stack. Using this simulation, we show that a tip-induced quantum dot formed near source and drain electrodes can be adiabatically moved to a region far from the gate electrodes. We argue that by spatially translating the tip-induced dot across a defect in the Si/SiGe interface, changes in valley splitting can be detected.

Related papers

• Cavity-enhanced superconductivity via band engineering [0.0]
  We consider a two-dimensional electron gas interacting with a quantized cavity mode. We find that the coupling between the electrons and the photons in the cavity enhances the superconducting gap.
  arXiv  Detail & Related papers  (2024-05-14T14:21:02Z)
• Mapping of valley-splitting by conveyor-mode spin-coherent electron shuttling [0.0]
  In Si/SiGe heterostructures, the low-lying excited valley state seriously limits operability and scalability of electron spin qubits. We introduce a method for two-dimensional mapping of the local valley splitting using entangled electron spin-pairs as a probe. Our method may become a valuable tool for engineering Si/SiGe heterostructures for scalable quantum computing.
  arXiv  Detail & Related papers  (2023-12-29T17:21:04Z)
• Interface and electromagnetic effects in the valley splitting of Si quantum dots [0.0]
  We investigate the influence of electromagnetic fields and the interface width on the valley splitting of a quantum dot in a Si/SiGe heterostructure. We propose a new three-dimensional theoretical model within the effective mass theory for the calculation of the valley splitting. We obtain a critical softness of the interfaces in the heterostructure, above which the best option for spin qubits is to consider an interface as wide as possible.
  arXiv  Detail & Related papers  (2023-03-23T20:30:53Z)
• Photon generation and entanglement in a double superconducting cavity [105.54048699217668]
  We study the dynamical Casimir effect in a double superconducting cavity in a quantum electrodynamics architecture. We study the creation of photons when the walls oscillate harmonically with a small amplitude.
  arXiv  Detail & Related papers  (2022-07-18T16:43:47Z)
• Triggering a global density wave instability in graphene via local symmetry-breaking [0.7437459197111806]
  Two-dimensional quantum materials offer a robust platform for investigating the emergence of symmetry-broken ordered phases. We show that an extremely dilute concentration of surface adatoms can trigger the collapse of the graphene atomic lattice into a distinct Kekul'e bond density wave phase. Our results demonstrate that dilute concentrations of self-assembled adsorbed atoms offer an attractive alternative route towards designing novel quantum phases in two-dimensional materials.
  arXiv  Detail & Related papers  (2022-04-23T05:58:00Z)
• Microwave-frequency scanning gate microscopy of a Si/SiGe double quantum dot [0.0]
  We combine scanning probe microscopy with the speed of microwave measurements in a Si/SiGe quantum dot. We resolve $sim$65 $mu$eV excited states, an energy scale consistent with typical valley splittings in Si/SiGe. Future extensions of this approach may allow spatial mapping of the valley splitting in Si devices.
  arXiv  Detail & Related papers  (2022-03-11T13:31:12Z)
• Three-fold way of entanglement dynamics in monitored quantum circuits [68.8204255655161]
  We investigate the measurement-induced entanglement transition in quantum circuits built upon Dyson's three circular ensembles. We obtain insights into the interplay between the local entanglement generation by the gates and the entanglement reduction by the measurements.
  arXiv  Detail & Related papers  (2022-01-28T17:21:15Z)
• Quantum correlations, entanglement spectrum and coherence of two-particle reduced density matrix in the Extended Hubbard Model [62.997667081978825]
  We study the ground state properties of the one-dimensional extended Hubbard model at half-filling. In particular, in the superconducting region, we obtain that the entanglement spectrum signals a transition between a dominant singlet (SS) to triplet (TS) pairing ordering in the system.
  arXiv  Detail & Related papers  (2021-10-29T21:02:24Z)
• Near-Field Terahertz Nanoscopy of Coplanar Microwave Resonators [61.035185179008224]
  Superconducting quantum circuits are one of the leading quantum computing platforms. To advance superconducting quantum computing to a point of practical importance, it is critical to identify and address material imperfections that lead to decoherence. Here, we use terahertz Scanning Near-field Optical Microscopy to probe the local dielectric properties and carrier concentrations of wet-etched aluminum resonators on silicon.
  arXiv  Detail & Related papers  (2021-06-24T11:06:34Z)
• Tunable Anderson Localization of Dark States [146.2730735143614]
  We experimentally study Anderson localization in a superconducting waveguide quantum electrodynamics system. We observe an exponential suppression of the transmission coefficient in the vicinity of its subradiant dark modes. The experiment opens the door to the study of various localization phenomena on a new platform.
  arXiv  Detail & Related papers  (2021-05-25T07:52:52Z)
• Observing localisation in a 2D quasicrystalline optical lattice [52.77024349608834]
  We experimentally and numerically study the ground state of non- and weakly-interacting bosons in an eightfold symmetric optical lattice. We find extended states for weak lattices but observe a localisation transition at a lattice depth of $V_0.78(2),E_mathrmrec$ for the non-interacting system.
  arXiv  Detail & Related papers  (2020-01-29T15:54:42Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.