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Nanonis Tramea

Customisable measurement system for quantum transport measurements.
Quantum transport measurements are complex time-critical procedures which look at the behaviour of electrons at low temperatures and in low dimensions.

Quantum Transport Measurements

Spin qubits in quantum dots are promising candidates for quantum computation. A fast measurement with a high number of inputs and outputs is critical for the efficiency of the development of multiple quantum dot devices. ​

Spin Qubits

The electronic structure of topological insulators can reveal unique topology leading to the formation of conducting surface states with intriguing properties. Rapid processing rate and precise control of settling and averaging time gives fast data acquisition

Topological Insulators​


Features

  • Up to 1000✕ 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 stabilised 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.
  • Scalable and expandable, the Tramea is the full replacement for the traditional measurement rack in a small footprint.

Options

The Nanonis Tramea base configuration provides the necessary elements required for performing high-speed DC transport measurements. It provides 8 precision, high-speed DC sources, 8 precision analog inputs, a full-featured software solution for data generation and acquisition and a powerful generic API.

All signal conditioning, FPGA and real-time signal processing are also included in the base configuration. It also includes the Tramea real-time Controller TRCe, Tramea Signal Conversion TSC and Nanonis software, as well as:​​

  • 8 analog inputs
  • 8 analog outputs
  • FPGA + real-time signal processing
  • Oscilloscope
  • Spectrum analyser
  • Powerful software measurement suite
  • High resolution data acquisition
  • 1D, 3D and N dimensional sweepers
  • Direct control of up to 4 external devices​​​
  • Control of MercuryiPS and MercuryiTC
  • Language independent programming interface.

As standard the Nanonis Tramea comes with 8 inputs and 8 outputs. With the combination of Tramea Signal Conversion units and Tramea Signal Output units, the Nanonis Tramea can have up to 24 precision DC inputs and up to 48 DC outputs. 

  • 16 BNC connectors (TSC = 8 inputs and 8 outputs, TSO = 16 outputs)
  • Differential input voltage range = ± 10 V
  • Output voltage range = ± 10 V into 1  or larger
  • Analog bandwidth = DC – 100 kHz (-3 dB) input, DC – 40 kHz (-3 dB) output
  • Input effective resolution = 20 bits at 60 kS/s, 22 bits at 1 kS/s
  • Output effective resolution = 22 bit patented hrDAC technology.

The table shows the numbers of input and outputs with different possible combinations of TSC and TSO.

By expanding the number of inputs and outputs with a combination of TSC and TSO units, there is no compromise on signal quality. The extra channels are integrated into the software, so there is no change in the workflow of the system and additional signals are seamlessly integrated into the Tramea software. 

TSC – Tramea Signal Conversion

For samples with large numbers of contacts and when external instruments deliver many signals which need to be digitised, 8 inputs and 8 outputs may not be enough.

An additional TSC gives you an extra 8 outputs and 8 inputs in addition to the 8 outputs and 8 inputs of the base configuration. Up to 2 extra TSCs on top of the base configuration can be used in combination with the base configuration to give as many as 24 inputs.

Options: Base configuration (1 TSC in total), TSC-1 (2 TSCs in total), TSC-2 (3 TSCs in total).

TSO – Tramea Signal Output

For devices that require a large number of gate voltages, the number of outputs required is usually much larger than the amount of signals to be digitised. 8 input channels of the Tramea base configuration may offer sufficient digitizing channels for most applications, but 8 output channels might not cover all the requirements for sample driving voltages.

An additional TSO immediately gives an extra 16 output channels to the 8 inputs and 8 outputs of the base configuration. Up to 2 TSOs can be added to the base configuration to give a maximum number of 40 outputs. When combining this with the TSC modules, a maximum number of 48 high precision, low-noise outputs can be provided.

Options: TSO-1 (1 TSO in total), TSO-2 (2 TSOs in total).

MCVA5 – Multichannel voltage preamplifier

The Nanonis MCVA5 differential multichannel preamplifier offers 4 independent differential channels. It provides low-noise amplification, very high input impedance, high common-mode rejection, gain up to 1000, and differential inputs.

The 4 differential inputs offer an input impedance greater than 10 TΩ to GND and very low input bias currents of less than 2 pA (typ.). They can be operated in either A-B (differential) or A (single-ended) mode or left floating, and they can be DC- or AC-coupled. The amplification circuit has user-selectable gains of 1, 10, 100 and 1000 and a bandwidth in excess of 500 kHz. Despite the very high input impedance spectral noise is as low as 4 nV/√Hz (SE, gain 100/1000)​.

The quantum dot simulator lets you explore the complete Nanonis Tramea measurement system as if it were connected to a real quantum dot. Learn the operation of the software without any risk. It simulates a typical single top-gate defined quantum dot and includes the full feature set of the software. Possible measurements include single gate sweeps, left- vs. right-gate sweeps as well as stability diagrams. Lock-in operation allows differential conductance measurements.


Software

Tramea is easily expandable for customised experiments using either the existing additional software modules or user-programmed functions.

The high performance digital lock-in amplifiers let you modulate and demodulate any of the input and output signals available with frequencies up to 40 kHz. Up to 8 lock-in modules can be used independently from each other or synchronised for phase-coherent operation. 

Up to 8 lock-in amplifiers - Up to 8 dual phase lock-in modules, modulating up to 8 of any output or input signal up to 40 kHz while using the high resolution 20-bit outputs.

Demodulator for lock-in amplifier - Extra demodulators for the dual lock-in module LD5-MF for use with single and dual lock-in. This gives the full 8 demodulators on the 2 lock-ins for multifrequency operation.

8 dual phase lock-in module with 8 independent frequency generators and 8 independent dual-phase demodulators.

An efficient method of adding feedback to the measurement system. It adds a flexible control loop functionality to the Tramea software.

  • Controls on any input or internal signal
  • Feedback signal can be applied on any output or internal signal
  • If-then mode for two-state control
  • DC or AC (lock-in) mode for temperature measurements, etc.
  • 6 kHz control bandwidth
  • Voltage limits for feedback signal
  • Up to 8 modules available.

                  Front panel of the PI controller

A function generator is often simpler and more efficient to use than scripts, when the same waveform or pulse sequence needs to be applied periodically. Any custom waveform can be uploaded and generate periodic patterns with a frequency between 500 mHz to 15 kHz by using the high precision and low noise 20-bit outputs. For higher slew rates the function generator can address the single fast analog output of the TSC offering 1 MHz analog bandwidth.

  • Arbitrary, user defined waveforms based on custom lookup tables
  • Suitable for pulsed-gate measurements, pattern-based measurements, etc.
  • Waveform duration from 2 s (0.5 Hz) to 67 µs (15 kHz)
  • 2 synchronized waveforms on different outputs
  • 20-bit waveform resolution, 16-bit amplitude and frequency scaling
  • 1 MS/s sampling rate
  • 500 kHz analog bandwidth on TSC fast output, 40 kHz analog bandwidth on normal outputs.

Front panel of the function generator software module

With the LabVIEW programming interface the user can design their own experiments and customise routines making full use of the LabVIEW scripts. 

The LabVIEW programming interface offers more functions and a simpler approach to programming than the TCP interface which is part of the base configuration, delivered as a standard API. 

Ready made example are available which can be used straight away or as a starting point for customised routines and external instruments are easily integrated.

LabVIEW VIs provided in the LabVIEW Programming Interface

The scripting module offers 100✕ faster execution speed, complementing the Nanonis Programming  Interface, which comes as standard in the base configuration. With a time-deterministic approach and 50 µs time interval between commands, scripting significantly boosts the execution speed, reducing measurement time. 

  • Up to 20,000 commands/s executed on a real-time system
  • Real-time execution of scripts for high speed execution
  • For-loops for automated measurement routines
  • If-commands for conditional execution and real-time feedback
  • Integration with the Programming Interface.

           Example of a script written using the scripting module

The high-resolution oscilloscope and spectrum analyser gives precise analysis in the frequency domain. For processes which take place in the ms and µs timeframes, standard oscilloscopes lack the combination of dynamic range, resolution and noise performance. The high resolution oscilloscope and spectrum analyser module overcomes the limitations a standard oscilloscope would have because of the precise and low noise 18-bit inputs of the TSC and the tight integration of the Nanonis software.

Transport measurements often need the acquisition of time dependent signals with typical time scales ranging from µs to minutes. The high resolution oscilloscope give access to data acquisitions up to 1 MSPS but also work with variable acquisition times and trace lengths up to 1 million points. It also provides high frequency resolution down to mHz range. 

  • Up to 1 million points per trace (user selectable), 1 MS/s sampling rate, 100 kHz analog bandwidth
  • Measurement time from 32 µs to 17 minutes, variable oversampling up to 1024
  • No need for input range adjustments: 18-bit resolution at 1 MS/s (22-bit at 1 kS/s) and lowest-noise input stage
  • No data loss thanks to pre-triggering. Triggering available both on analog signals and digital lines
  • 500’000-point FFT for precise frequency determination and noise analysis.

                       High resolution oscilloscope


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