Skip to content

Towards detecting traces of non-contact quantum friction in the corrections of the accumulated geometric phase

MetadataDetails
Publication Date2020-02-19
Journalnpj Quantum Information
AuthorsM. Belén Farías, Fernando C. Lombardo, Alejandro Soba, Paula I. Villar, Ricardo S. Decca
InstitutionsUniversity of Indianapolis, ComisiĂłn Nacional de EnergĂ­a AtĂłmica
Citations35
AnalysisFull AI Review Included

6CCVD Technical Documentation: Quantum Friction Detection using Diamond NV Centers

Section titled “6CCVD Technical Documentation: Quantum Friction Detection using Diamond NV Centers”

This document provides a technical analysis of the research paper “Towards detecting traces of non-contact quantum friction in the corrections of the accumulated geometric phase” and outlines how 6CCVD’s advanced MPCVD diamond products and engineering services can facilitate the replication and extension of this groundbreaking quantum information experiment.


The attached research outlines a feasible experimental scheme to indirectly detect traces of non-contact Quantum Friction (QF) by measuring decoherence effects on a Nitrogen-Vacancy (NV) center in diamond.

  • Core Achievement: Proposes the first experimentally viable scheme to track traces of QF by measuring velocity-dependent corrections to the Geometric Phase (GP) accumulated by a two-level system.
  • Sensing Mechanism: Utilizes an NV center spin qubit (a point-like discrete energy level quantum system) in diamond as the sensor.
  • Experimental Challenge: Requires maintaining a highly stable nanometer-scale gap (3-10 nm) between the diamond NV sensor (on an AFM tip) and a high-speed rotating metallic (Au or n-Si) disk.
  • Material Necessity: Success depends critically on high-purity Single Crystal Diamond (SCD) for stable NV center coherence and ultra-flat surfaces (Ra < 1 nm) for stable AFM distance control.
  • Engineering Requirement: The setup necessitates large-diameter (12 cm) substrates and precise metalization capabilities (Au deposition) to achieve the necessary tangential velocities and plasma frequencies.
  • 6CCVD Value Proposition: 6CCVD offers custom SCD wafers up to 500 ”m thickness, precision polishing (Ra < 1 nm), and in-house metalization (Au, Ti, Pt, etc.) essential for replicating the proposed experimental geometry and material conditions.

The following hard data points define the requirements and parameters of the proposed experiment, focusing on the material and engineering constraints.

ParameterValueUnitContext
Core Sensor SystemNV Center in Diamond-Effective two-level quantum system (qubit).
Measurable Phase Change~50mradRequired detection sensitivity over 106 repetitions.
Target Separation (a)3 to 10nmDistance between the AFM tip NV center and the rotating disk surface.
Separation Control Stability (ÎŽa)1nmMaximum tolerated fluctuation in the gap (critical to prevent spurious decoherence).
Substrate ConfigurationSi Disk, Metal Laminated-Tested coatings: Au and n-doped Si.
Required Disk Diameter12cmNecessary dimension for the high-speed rotating table.
Maximum Angular Velocity (Ω)$2\pi \times 7000$rad/sAchievable rotation speed for generating relative motion.
Dimensionless Velocity (u) (n-Si)0.0025-Velocity required for QF detection when using n-doped Si coating.
Au Plasma Frequency ($\omega_{pl}$)$1.37 \times 10^{16}$rad/sDrude-Lorentz model parameter for the metallic coating.
Disk Vertical Wobble Tolerance1nmMaximum allowed vertical motion at the disk edge during rotation.
Experiment Feasibility TimelineN >> 5 cycles-Minimum number of cycles required for the accumulated GP correction to become relevant.

The proposed experiment tracks QF through velocity-dependent GP corrections ($\delta\phi_{u \ne 0}$) relative to the zero-velocity correction ($\delta\phi_{u=0}$) induced by the quantum field.

  1. NV Center Integration: A single NV center in a high-purity diamond crystal is integrated onto a modified Atomic Force Microscope (AFM) cantilever tip, serving as the moving two-level system.
  2. Substrate Preparation: A 12 cm diameter Si disk is prepared and coated with either a metallic layer (Au) or a conductive semiconductor (n-doped Si).
  3. High-Speed Relative Motion: The coated Si disk is mounted on a high-speed turntable capable of rotation speeds up to $2\pi \times 7000$ rad/s.
  4. Nanoscale Gap Maintenance: The AFM feedback control system actively maintains a constant, precise separation ($a$) between the NV tip and the rotating disk surface within ±1 nm fluctuation (targeting $a$ in the 3-10 nm range).
  5. Geometric Phase Measurement: Using Ramsey interferometry or similar phase detection techniques, the GP accumulated by the NV center is measured over many cycles ($N$).
  6. Velocity Dependence Analysis: The correction to the unitary GP ($\delta\phi$) is analyzed as a function of the tangential velocity ($u$) of the NV center relative to the disk, with the velocity contribution ($\delta\phi_{u \ne 0}$) isolating the QF effect.

This research relies on cutting-edge material science, particularly in Single Crystal Diamond (SCD) quality, surface engineering, and custom metalization. 6CCVD is uniquely positioned to supply the materials required to successfully execute and advance this research into non-contact quantum friction.

Research Requirement6CCVD Solution & CapabilityEngineering & Sales Benefit
High-Coherence Qubit HostOptical Grade Single Crystal Diamond (SCD)Provides the lowest defect density material necessary to ensure the long spin coherence times (T2) essential for the NV center to accumulate the GP over many cycles (N >> 5) before decoherence occurs.
Ultra-Flat Sensing SurfaceSCD Polishing: Ra < 1 nm (standard for SCD)Critical requirement for maintaining the necessary 3-10 nm separation stability (±1 nm). Low roughness prevents spurious decoherence effects induced by distance fluctuations ($\delta a$).
Custom Metallic SubstrateIn-House Metalization (Au, Pt, Ti, W, Cu)The paper specifies an Au coating. 6CCVD provides direct, custom metal deposition services, ensuring the specified plasma frequency ($\omega_{pl}$) characteristics are achieved consistently on the diamond substrate.
Large-Area RequirementsCustom PCD Wafers up to 125 mmWhile the sensor (NV tip) is SCD, the rotating disk geometry (12 cm diameter) requires large-scale capabilities. 6CCVD can supply large PCD wafers suitable for high-speed rotation stability or coated Si wafers, leveraging our extensive size capabilities.
Conductive Diamond AlternativeHeavy Boron-Doped Diamond (BDD)The paper proposes n-doped Si. BDD is a superior, highly stable conductive platform. 6CCVD can produce BDD plates up to 500 ”m thick, offering an alternative to n-Si for simulating conductive dielectric environments for QF studies.
International Supply ChainGlobal Shipping (DDU default, DDP available)Ensures rapid and reliable delivery of specialized diamond components and metalized substrates to research teams worldwide, maintaining project timelines.

6CCVD’s in-house PhD engineering team specializes in diamond material science for quantum applications. We can assist researchers in selecting the optimal MPCVD diamond specifications (SCD orientation, doping levels, and metal layer thicknesses) required to replicate the velocity-dependent GP measurements for Quantum Friction projects.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Abstract The geometric phase can be used as a fruitful venue of investigation to infer features of the quantum systems. Its application can reach new theoretical frontiers and imply innovative and challenging experimental proposals. Herein, we take advantage of the geometric phase to sense the corrections induced while a neutral particle travels at constant velocity in front of an imperfect sheet in quantum vacuum. As it is already known, two bodies in relative motion at constant velocity experience a quantum contactless dissipative force, known as quantum friction. This force has eluded experimental detection so far due to its small magnitude and short range. However, we give details of an innovative experiment designed to track traces of the quantum friction by measuring the velocity dependence of corrections to the geometric phase. We notice that the environmentally induced corrections can be decomposed in different contributions: corrections induced by the presence of the dielectric sheet and the motion of the particle in quantum vacuum. As the geometric phase accumulates over time, its correction becomes relevant at a relative short timescale, while the system still preserves purity. The experimentally viable scheme presented would be the first one in tracking traces of quantum friction through the study of decoherence effects on a NV center in diamond.

  1. 2003 - The Quantum Vacuum
  2. 2009 - Advances in the Casimir Effect [Crossref]
  3. 2001 - The Casimir Effect: Physical Manifestations of the Zero- Point Energy [Crossref]