In situ tuning hydrostatic pressure at low temperature using electrically driven diamond anvil cell

At a Glance

Metadata	Details
Publication Date	2016-01-01
Journal	Acta Physica Sinica
Authors	Kun Ding, Wu Xue-Fei, Dou Xiu-Ming, Sun Bao-Quan
Citations	2
Analysis	Full AI Review Included

Technical Documentation & Analysis: PZT-Driven Low-Temperature Diamond Anvil Cell

Reference: Ding Kun, Wu Xue-Fei, Dou Xiu-Ming, Sun Bao-Quan. In situ tuning hydrostatic pressure at low temperature using electrically driven diamond anvil cell. Acta Physica Sinica, 65, 037701 (2016).

Executive Summary

This research details the development of an electrically driven Diamond Anvil Cell (DAC) system, enabling precise, continuous hydrostatic pressure tuning at cryogenic temperatures. This innovation is critical for advanced quantum and condensed matter physics experiments.

Core Innovation: Replaces traditional mechanical screws or helium-driven pistons with a Piezoelectric Actuator (PZT) for pressure application in a DAC.
Performance: Achieved continuous pressure tuning from 0.49 GPa to 4.41 GPa at stable low temperatures (19 ± 1 K).
Cryogenic Stability: Demonstrated exceptional temperature stability, with the chamber temperature varying by less than 2 K across the entire 4 GPa tuning range.
Precision Tuning: The PZT mechanism allows for high-resolution pressure adjustment by controlling the applied voltage, crucial for tracking subtle material property changes in situ.
Application Focus: Successfully used to tune the emission wavelength of InAs Quantum Dots (QDs) to match a microcavity mode, proving its utility for compact tunable single-photon sources and quantum interference experiments (e.g., NV centers in diamond).
Material Requirement: Relies fundamentally on the high optical transparency and mechanical strength of Single Crystal Diamond (SCD) anvils, which serve as both the pressure interface and the optical window (Bandgap: 5.47 eV).

Technical Specifications

The following hard data points were extracted from the experimental results regarding the PZT-driven DAC system performance:

Parameter	Value	Unit	Context
Pressure Tuning Range	0.49 - 4.41	GPa	Continuous hydrostatic tuning capability
Operating Temperature (Chamber)	18 - 20 (± 1)	K	Stable temperature during pressure sweep
Maximum Applied Voltage (PZT)	290	V	Required to achieve maximum pressure
PZT Stroke (300 K)	40	µm	Maximum stroke at 120 V (Room Temp)
PZT Stroke (80 K)	26	µm	Maximum stroke at 120 V (Low Temp)
PZT Stroke (6 K)	15	µm	Maximum stroke at 120 V (Cryogenic)
Temperature Stability (ΔT)	< 2	K	Variation across the 4 GPa tuning range
Pressure Calibration Method	Ruby Fluorescence	N/A	Uses R₁ and R₂ peak shifts
Optical Window Material	Diamond	N/A	Required bandgap of 5.47 eV
Sample Application	InAs Quantum Dots	N/A	Demonstrated tuning of PL peak

Key Methodologies

The experiment successfully integrated a piezoelectric actuator (PZT) into a standard DAC setup to achieve continuous, low-temperature pressure tuning.

DAC Integration: A traditional DAC head (including diamond anvils and loading screws) was assembled within a red copper cylinder (Component 6) for thermal contact and stability.
PZT Selection: A Piezomechanik PSt 150/10×10/40 PZT was selected, capable of generating a maximum thrust of 8000 N, sufficient for the required GPa pressures.
Cryogenic Setup: The assembled DAC/PZT unit was fixed to the cold head of a cryostat (e.g., Montana or MicrostatHiResII). The red copper cylinder ensured thermal contact for cooling the DAC chamber.
Initial Loading: An initial pressure of 0.49 GPa was set at room temperature using the traditional mechanical loading screws (Component 2) before cooling.
Pressure Tuning: Once cooled to 20 K, pressure was continuously increased in situ by applying voltage (0 V to 290 V) to the PZT, leveraging the PZT’s length extension (stroke).
Calibration:
- Pressure: Determined by measuring the red shift of the Ruby R₁ fluorescence line.
- Temperature: Determined by measuring the intensity ratio (R₂/R₁) of the Ruby fluorescence lines, confirming chamber temperature stability (18-20 K).
Application Demonstration: The system was used to precisely shift the photoluminescence (PL) peak of InAs QDs to achieve resonance coupling with a microcavity mode at 20 K.

6CCVD Solutions & Capabilities

The successful replication and extension of this high-pressure, low-temperature quantum research fundamentally depends on the quality and precision of the diamond anvils. 6CCVD is uniquely positioned to supply the necessary MPCVD diamond materials and customization services.

Applicable Materials

To achieve the high optical transparency (5.47 eV bandgap) and mechanical integrity required for DAC anvils operating under GPa pressures and cryogenic temperatures, Optical Grade Single Crystal Diamond (SCD) is mandatory.

6CCVD Material Recommendation	Key Features for DAC Application
Optical Grade SCD	Ultra-low nitrogen content (Type IIa equivalent) ensuring high transparency across UV-Vis-IR spectra, critical for PL, Raman, and absorption spectroscopy.
High Purity SCD	Superior mechanical strength and hardness required to withstand pressures up to 4.41 GPa (and beyond) without failure or plastic deformation.
BDD (Boron-Doped Diamond)	Potential Extension: For experiments requiring integrated electrical sensing or heating elements directly on the anvil surface, BDD can be used as a conductive layer or sensor.

Customization Potential

DAC anvils require extremely precise geometry and surface finish to ensure uniform pressure distribution and maximize optical throughput. 6CCVD’s advanced fabrication capabilities directly address these needs:

Custom Dimensions and Geometry: 6CCVD provides SCD plates and wafers up to 125mm. We specialize in custom laser cutting and shaping of anvils, including precise culet diameters and specific bevel angles required for high-pressure physics (e.g., 16-sided anvils, beveled anvils).
Ultra-Low Roughness Polishing: The optical surface (culet face) must be near-perfect. We guarantee Ra < 1 nm polishing on SCD, minimizing light scattering and maximizing signal quality for sensitive measurements like PL and Raman spectroscopy.
Integrated Metalization: While this paper did not detail integrated sensors, many advanced DAC experiments require thin-film electrodes or heating elements. 6CCVD offers in-house metalization services, including deposition of Ti/Pt/Au, W, Cu, and Pd layers, directly onto the diamond surface for integrated electrical contacts or resistive heating.

Engineering Support

The successful implementation of PZT-driven DACs for quantum applications (e.g., tuning NV centers in diamond, QDs, or single-photon sources) requires careful material selection and design optimization.

Cryogenic Compatibility: 6CCVD’s in-house PhD team provides consultation on selecting the optimal diamond material and geometry to minimize thermal stress and ensure mechanical stability when cycling between 300 K and 4 K.
High-Pressure Design: We assist engineers in optimizing anvil geometry (culet size, thickness) to achieve target pressure ranges (up to 500 GPa using specialized geometries) while maintaining the required optical access.
Quantum Applications: Our experts can guide researchers in selecting diamond substrates suitable for hosting or interfacing with quantum emitters, ensuring low defect density and high optical quality for similar InAs Quantum Dot or Nitrogen Vacancy (NV) Center projects.

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

View Original Abstract

Traditionally, a diamond anvil cell (DAC) operated at low temperature can be pressurized by using a helium-driven piston or remote control tightening mechanism. This approach of pressurizing DAC is not convenient for operating at low temperature. Here we develop a low-temperature pressurizing technique for in situ tuning pressure in DAC at 20 K by an electrically driven method. The improved DAC pressure apparatus is composed of traditional DAC device and a piezoelectric actuator (PZT). Here the PZT used in the experiment is the PSt 150/1010/40 supplied by the Piezomechanik. Both parts are assembled together in a red copper or stainless steel cylinder. The DAC part is thermally contacted with a low temperature holder for cooling the chamber of the DAC in the experiment. The wires of the PZT connect with the voltage source through the wiring terminals of the cryostat. As the DAC apparatus cools down, two electrodes of the PZT are connected together when a voltage difference between the electrodes is generated. When the temperature of the DAC chamber arrives at the presetting value, two electrodes of the PZT are connected with the voltage source for applying voltage to the PZT. In this paper, we find that the PZT stroke shows a linear increase with increasing voltage at 300 K, whereas it is approximately linear at 80 and 6 K. The maximum strokes are 40, 26 and 15 upm at 300, 80 and 6 K respectively when the applied voltage is 120 V. The experimental results show that the PZT-driven DAC apparatus can continuously generate pressure from 0.49 to 4.41 GPa at low temperature and applied voltage of 0-290 V, where at zero voltage an initial pressure of 0.49 GPa is generated by using driven screws of the DAC device at room temperature. The pressure in the DAC chamber is determined by the red shift of ruby florescence line. The calibrated chamber temperature in DAC is determined as a function of pressure (PZT voltage) by using the intensity ration (R2/R1) of ruby R2 and R1 fluorescence lines. We find that the chamber temperature only slightly increases with increasing pressure in a range of (19 1) K. The main difference between the present device and the other tuning DAC apparatus is that the force on the DAC can be conveniently applied by using PZT voltage. This guarantees a high pressure-tuned resolution in the experiment, e. g., we tune a single InAs quantum dot (QD) emission wavelength to match the cavity mode. Such a tuning technique is found to have applications in realizing a compact tunable single photon source or completing two-photon interference of Hong-Ou-Mandel experiments between the QD and nitrogen vacancy center in diamond or atom, respectively.

Tech Support

Original Source

DOI: https://doi.org/10.7498/aps.65.037701