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Tramea base configuration

The Nanonis Tramea™ base configuration is the core unit of a Nanonis quantum transport measurement system

Nanonis Tramea base configuration
Nanonis Tramea base configuration: TRC real-time controller, TSC signal conversion interface and Nanonis software

The Nanonis Tramea™ base configuration provides all elements required for performing high-speed DC transport measurements: 8 precision, high-speed DC sources, 8 precision analog inputs, and a full-featured software solution for data generation and acquisition. All signal conditioning, FPGA and real-time signal processing are also included in the base configuration, which offers a complete framework that can be adapted and extended with a wide range of add-on modules.

Base configuration: Real-time Controller, Signal Conversion unit and Nanonis software.

More details about the base configuration can be found below or on the Tramea main page

KEY FEATURES

  • Up to 1000x faster than conventional measurement solutions
  • Fully integrated digital system: avoid complex wiring
  • Integrated safety measures: avoid damaged samples
  • Lower output noise than most dedicated DC sources
  • High-resolution DA conversion: true-20-bit analog outputs, 22-bit with hrDAC
  • High resolution AD-conversion: Up to 22-bit
  • Temperature stabilized for lowest drift
  • Lock-ins with over 100 dB dynamic reserve    
  • Fully asynchronous multi-tasking user interface
  • Software instruments instead of hardware boxes for more performance, flexibility and upgradeability
  • Oscilloscopes, spectrum analyzers, data loggers, charts and graphs
  • Easy customization through various programming options

Plenty of channels

The system handles 128 live signals in real-time: Up to 48 outputs, up to 24 inputs with the remaining signals being user configurable internal signals. Up to 24 signals can be acquired simultaneously with up to 8 additional signals streamed to disk at up to full ADC speed. The base configuration offers 8 inputs and 8 outputs and can be flexibly expanded with additional TSC or TSO signal interfaces.

This very large number of live signals can not only be monitored, but also all signals are displayed as real world numbers in floating- point representation, with assigned SI units for immediate quantitative results, without the need of additional calibrations during data analysis.

Signal analysis and monitoring

All signals can be inspected with the FFT spectrum analyzer, dual-channel oscilloscope, signal charts, and history panels. Such fully digital and integrated software instruments are much more efficient in use, less invasive, better in performance, and lower in cost than their external counterparts.

The ability to digitally route live signals to software instruments during active measurements without any negative impact on signal quality is truly invaluable when optimizing the experimental set-up, eliminating disturbances and thus improving the quality of scientific results.

High resolution AD/DA conversion

The signal frontend of the base configuration, the Nanonis TSC, uses the latest advances in AD/DA conversion technology, in combination with sophisticated digital filtering, oversampling, and dithering techniques, to provide the highest resolution.

All outputs of the TSC and TSO use 20-bit resolution DACs with 1-ppm precision, the best available on the market. just a few years ago, similar performance on multiple outputs would have been impossible to realize. The patented hrDAC™ technology turns these state-of-the-art converters into real 22-bit devices, which in a traditional approach would fill a rack with single-channel instruments and cost ten times as much.

Measurements requiring very small modulations with large offsets are thus possible without the need for drift- and error-inducing analog circuits or external mixers or attenuators. The impressive dynamic range also eliminates the need for switching gains.

Lowest noise and drift

When experiments involve energies of a few μeV, high resolution alone is not the only pre- requisite for a measurement interface: Low noise is of utmost importance, and the TSC delivers impressive performance on both inputs and outputs. The noise floor of the TSC and TSO lies below 25 nV/√Hz with an output voltage range of ±10 V. Despite its large bandwidth of 40 kHz, the output noise does not exceed 10 μV RMS at a measurement bandwidth of 300 kHz, meaning that the noise contribution of the SC5 is irrelevant in experimental situations.

Scanning probe microscopes require very stable signals over long measurement times. For this reason, the TSC5 and TSO are equipped with a custom temperature-stabilized, high precision voltage reference. The reference has a very low inherent noise and drift. Temperature stabilization combined with thermal decouplingallows reduction of the temperature coefficient to below 3 μV/°C and output drift to below 1.5 μV in 12 hours at 0 V.

In contrast to broadband noise, which can be easily filtered, 1/f noise cannot be eliminated and becomes an issue for experiments requiring signals to be very stable. The outputs of the TSC and TSO have been designed keeping this in mind, leading to a noise level below 750 nV peak- peak (0.1 – 10 Hz, ±10 V range), or about 223 times smaller than the maximum output signal.

Optimal SNR for small signals

A custom-designed input stage allows acquisition of the weakest analog signals, without compromises in dynamic range. The signals are digitized at an early stage with 18-bit AD converters running at 1 MS/s and then processed in the digital domain. Adaptive over- sampling is used to always obtain the best signal-to-noise ratio for a given data acquisition rate.

Intelligent adaptive oversampling adds an additional degree of intelligence to data acquisition: Measurement speed can be adapted automatically to the actual value and required quality of the input signal. This results in faster measurements for intervals where no interesting input signal is expected (e.g. just noise) and in higher quality data for the measurement ranges of interest. Instead of guessing integration times, the system automatically determines the optimal value for each measurement point based on signal noise and amplitude.

For even smaller signals, for direct measurements of high-resistance samples, for true differential measurements or simply for extremely small signals, the newly developed MCVA5 voltage amplifier is the ideal frontend to the SC5. It provides staggering 10 TΩ input impedance (to GND), an input spectral noise below 4 nV/√Hz (single-ended at 1 kHz and gain 100), over 120 dB of common-mode rejection and over 500 kHz bandwidth at any gain setting. Remote control is provided for gain (1, 10, 100, 1000), coupling (DC, AC) and input mode (A, A-B).

The preamplifier is seamlessly integrated into the Nanonis software meaning that all calibrations are automatically adjusted when the gain is switched. The design ensures exceptional low-frequency performance resulting in a noise density below 11 nV/√Hz at 1 Hz and 0.1-10 Hz noise of only 25 nV rms (gain 100, single-ended).

Nanonis Tramea software: The most advanced user interface for transport measurements

The user interface is the crucial part of the measurement system when recording of high quality data in a short time is required. The growing complexity of quantum transport measurements requires control and visualization of a large number of parameters in real-time. At the same time, sensitive samples do not tolerate user errors, meaning that the user interface should ensure that no sample can be damaged by erroneous user inputs.

To ensure that the user is not overwhelmed by the resulting experimental complexity, the user interface is designed based on the typical measurement workflow, with all functions accessible but with the option to only display the relevant ones. A streamlined design ensures that the software is easy to use and that even inexperienced users can work more productively and safely.

More details about the software can be found in the Tramea software page

Customization

Competitive advantage in research is often based on the modification of an instrument that allows the researcher to perform experiments in a way nobody else has done before. This is where the built-in API steps in: to give you the building blocks to design your own experiment. It is used to automate experiments, sequences, calibration routines and experimental procedures. Polling of parameters and signals at high rates allows for supervision and alarm settings, and many other features. The user can program in any programming language able to write to and read from a TCP port on the host PC, including Python, Matlab or C++, using a generic script format.

For users preferring an easier start in experiment programming, or users which are used to a LabVIEW programming environment, the LabVIEW programming interface add-on module is the ideal API choice. The LabVIEW programming interface adds the ease of use and debugging options of LabVIEW and consists of libraries to access the controls and functions of the graphical user interface. With the LabVIEW interface the Nanonis SPM Control System provides full access to all the features provided with LabVIEW: graphs, database access, convenient data handling, TCP/ IP, GPIB, RS232, USB access to other instruments, signal analysis functions and much more.

For experiments where exact timing is crucial, the scripting add-on module becomes the ideal tool for customization: Scripts are executed on the real- time system in a time-deterministic manner, improving the time response by a factor of 100 compared to the programming interface. Logic functions can be implemented with the use of FOR loops and IF conditions, for example for real-time feedback. Triggering over TTL lines directly from the real-time system is ideal for fast synchronization with external equipment.

MADE FOR THESE METHODS

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SPECIFICATIONS

Tramea base configuration
Performance
Analog inputs

If not otherwise specified, all specifications for ±10 V input range

Number of Connectors

8x BNC connector, differential

Differential input voltage range

± 10 V

Differential input voltage range

±10 V, ±1 V, ±100 mV, ±10 mV (with MCVA5)

Differential input impedance

2 MΩ

Input impedance

>10 TΩ to GND, >50 GΩ differential (with MCVA5)

Input bias current

<2 pA typ. (with MCVA5)

Analog bandwidth

DC – 100 kHz (-3 dB), 5th-order Butterworth low-pass filter

AD-converter

18-bit, no missing codes, 1 MS/s

Effective resolution

20-bit @ 60 kS/s, 22-bit @ 1 kS/s (oversampling)

INL

±2 LSB typical

DNL

±1 LSB typical

Input noise density

< 150 nV/√Hz @ 10 kHz, < 650 nV/√Hz @ 10 Hz

Input noise density

<4 nV/√Hz (<5.5 nV/√Hz) @10 kHz SE (differential)
< 5 nV/√Hz (<6 nV/√Hz) @ 10 Hz SE (differential)
<11 nV//√Hz (<15 nV/√Hz) @ 1 Hz SE (differential)
(With MCVA5 @ gain 100)

Input measurement noise

< 100 μVrms @ 1 MS/s, < 25 μVrms @ 60 kS/s, < 6.5 μVrms @ 240 S/s

Input noise 0.1 Hz - 10 Hz

<25 nVrms (< 32 nVrms) SE (differential)
(With MCVA5 @ gain 100)

12 h drift

< 80 μV (< 100 μV) @ 0 V (@ 9.9 V)

THD+N

> 120 dB @ 100 Hz, > 95 dB @ 1 kHz,
> 70 dB @ 10 kHz (9 V input signal)

CMRR

>125 dB @ 10 Hz >120 dB @ 100 Hz >100 dB @ 1 kHz (with MCVA5 @ gain 100)

Analog outputs

all specifications for ±10 V output range

Number of Connectors

8 x BNC connectors (TSO: 16x BNC connectors), referenced to AGND

Output voltage range

±10 V into 1 kΩ or larger
(0 to +10 V with internal jumper per channel)

Output impedance

<1 Ω, short circuit safe

Analog bandwidth

DC – 40 kHz (-3 dB),
5th – order Butterworth low-pass filter

DA-converter

20-bit, 1-ppm precision, 1 MS/s

Effective resolution

22-bit, patented hrDACTM technology with active glitch compensation

INL

< ±2 LSB max. < ±1 LSB typical

DNL

< ±1 LSB max. < 0.5 LSB typical

Output noise density

< 25 nV/√Hz @ 100 Hz, < 75 nV/√Hz @ 1 Hz

Output noise 0.1 Hz - 10 Hz

< 200 nVrms (0.1 – 10 Hz)

Output noise 10 Hz - 300 kHz

< 10 μVrms (10 Hz – 300 kHz)

12 h drift

< 1.5 μV (< 25 μV) @ 0 V (@ 9.9 V)

THD+N

> 93 dB @ 100 Hz, > 93 dB @ 1 kHz, > 79 dB @ 10 kHz (9V output signal)

Digital lines

  

Number of Connectors

4 x 8 bidirectional lines on four D-sub 9 female connectors

Signal

3.3 V TTL, max. 25 mA per line

Maximum sampling frequency

500 kHz

High-speed digital lines

  

Number of Connectors

4 x inputs and 4 x outputs on SMB male connectors

Signal

3.3 V TTL, max. 33 mA per line

Maximum sampling frequency

200 MHz

Clock

  

Number of Connectors

1 x input, 1 x output for active clock source on SMB male connectors

Frequency

10 MHz, square wave, 3.3 V

Accuracy

± 50 ppm (standard clock), ± 4 ppm (optional OCXO)

Operation
Operating temperature

+5° C to +35° C

Power Supply

TRCe: Built-in universal power supply, max. 220 W

Power Supply

TSC: Built-in linearly regulated power supply, toroidal transformer, automatic line voltage detection. Max. 51 W

Power Input

TRCe: 100 – 230 V, 50 - 60 Hz

Power Input

TSC: 100 – 240 V, 50 - 60 Hz

Real-time system

NI PxIe-8840 real-time system with Intel Corei5 CPU 2.7 GHz, 4 GB RAM

Operating system

NI LabVIEW Real-Time OS

FPGA card

NI PXIe-7976

Connectivity

3x TSC max., 2x TSO max. Total of max. 4 frontends

Electrical GND

10 kΩ AGND to chassis, decoupled from RC5e

Data transfer

Via TCP/IP, 2 kS/s default, up to 20 kS/s, 1 MS/s x 8 channels for data streaming

Mounting
Dimensions

32.5 x 28 x 21 cm (TRCe)

Dimensions

32.5 x 28 x 7 cm (TSC)

Weight

8 kg (TRCe)

Weight

4.2 kg (TSC)

RELATED PRODUCTS

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APPLICATION NOTES

Topological Insulator Josephson junctions
Topological Insulator Josephson junctions
In a topological insulator (TI), the electronic structure of the bulk reveals a unique topology that leads to the formation of conducting surface states with intriguing properties. The topological protection of the surface states and the possible emergence of Majorana fermions in superconductor/TI hybrid devices make these materials a leading candidate for use as a robust platform for future fault-tolerant quantum computation. The main challenge in creating these structures lies in the fabrication of an electrically transparent interface between the conventional superconductor and the topological insulator. A Josephson junction, formed by two closely spaced superconducting electrodes separated by a gap of less than 100 nm, can be used as a measure of the quality of the electrical interface. At low temperatures the superconducting electrodes induce superconductivity in the topological insulator by the proximity effect, with a finite Josephson current observed across a sufficiently narrow gap.
download PDF
Measuring Electron Temperature using Nanonis Tramea
Measuring Electron Temperature using Nanonis Tramea
The Nanonis Tramea Quantum Transport Measurement System (QTMS) was used to measure electron transport through an electrostatically defined Gallium Arsenide (GaAs) quantum dot in an Oxford Instruments Triton 200 dilution refrigerator. The high-speed demonstrated by Nanonis Tramea allowed for a significant reduction in the measurement acquisition time and the low noise environment of the Oxford Instruments dilution refrigerator combined with the Tramea system, allowed us to measure an electron temperature of 35 mK. This was equal to the base temperature of the cryostat with customised wiring installed.
download PDF
Characterization of Germanium Nanowire
Characterization of Germanium Nanowire
Using a combination of the Nanonis Tramea quantum transport measurement system fully integrated with an Oxford Instruments HelioxVL refrigerator, the energy levels of a qubit have been successfully measured in a Germanium nanowire. Due to the lower noise and faster speed of this measurement system, conduct-ance measurements with greater detail are produced in shorter acquisition times.
download PDF
Transport and RF-Reflectometry Measurements of CMOS Nanodevices
Transport and RF-Reflectometry Measurements of CMOS Nanodevices
Pioneering work on semiconductor quantum dots has shown that quantum dots are promising candidates as a building block (qubit) for quantum information and computation. Quantum dots are quasi-zero-dimensional nanostructures which can confine single electrons, whose spin or charge degree of freedom can then be used to represent quantum bits (qubits). Quantum computing approaches based on semiconductors can build upon mature micro/nano-fabrication technologies, which will be invaluable in scaling up to a large number of reproducible qubits with practical yields and integrated electronics. As part of the classical information technology industry, CMOS transistors have reached sufficiently small feature sizes that quantum effects can begin to play a dominant role. This motivates the exploration of quantum effects in such transistors fabricated using CMOS processes.
download PDF
Tuning and Operation of Quantum Dots and Related Apparatus
Tuning and Operation of Quantum Dots and Related Apparatus
Spin qubits in quantum dots are promising candidates towards quantum computation. However, a considerable amount of technical development is still necessary before the advent of a quantum computer. For quantum dots, this involves independently controlling and sweeping the voltages of a multitude of electrostatic gates and monitoring several charge sensing signals. Thus, a fast measurement device with a high number of inputs and outputs is critical for the efficiency of the development of multiple quantum dot devices. The group of Michel Pioro-Ladrière at Institut Quantique, Université de Sherbrooke, Canada, have recently conducted measurements on quantum dots and related components using the Nanonis Tramea instrument, which will be discussed in this application note.
download PDF
Physics on the Level of Single Electrons
Physics on the Level of Single Electrons
When shrinking the size of physical systems, it often becomes unclear in which way the physical laws are still valid. For example, thermodynamics is a phenom-enological theory which relies on the assumption that the system under consideration consists of a large (approximated by infinitely many) number of particles. When this limit - the so-called thermodynamic limit - does not hold, fluctuations dominate the physics, and the thermodynamic laws need to be corrected. Howev-er, when considering smaller physical systems, not only the number of particles, but also the dimensional-ity of the system might change. Many laws have been derived for two-dimensional systems, and can be dif-ferent for the case of one or zero dimensional systems.
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PUBLICATIONS

  1. (2019) Gate Tunable Hole Charge Qubit Formed in a Ge/Si Nanowire Double Quantum Dot Coupled to Microwave Photons

    A controllable and coherent light-matter interface is an essential element for a scalable quantum information processor. Strong coupling to an on-chip cavity has been accomplished in various electron quantum dot systems, but rarely explored in the hole systems. Here we demonstrate a hybrid architecture comprising a microwave transmission line resonator controllably coupled to a hole charge qubit formed in a Ge/Si core/shell nanowire (NW), which is a natural one-dimensional hole gas with a strong spin–orbit interaction (SOI) and lack of nuclear spin scattering, potentially enabling fast spin manipulation by electric manners and long coherence times. The charge qubit is established in a double quantum dot defined by local electrical gates. Qubit transition energy can be independently tuned by the electrochemical potential difference and the tunnel coupling between the adjacent dots, opening transverse (σx) and longitudinal (σz) degrees of freedom for qubit operation and interaction. As the qubit energy is swept across the photon level, the coupling with resonator is thus switched on and off, as detected by resonator transmission spectroscopy. The observed resonance dynamics is replicated by a complete quantum numerical simulation considering an efficient charge dipole-photon coupling with a strength up to 2π × 55 MHz, yielding an estimation of the spin-resonator coupling rate through SOI to be about 10 MHz. The results inspire the future researches on the coherent hole-photon interaction in Ge/Si nanowires.



    R. Wang, R. S. Deacon, J. Sun, J. Yao, C. M. Lieber and K. Ishibashi
    Nano Lett. 2019, 19, 2, 1052-1060
    Read more

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