Functional Overview

This chapter provides the overview of the features provided by the SHFQC Instrument. The first section contains the description of the functional diagram and the hardware and software feature list. The next section details the front panel and the back panel of the measurement instrument. The following section provides product selection and ordering support.

Features

The SHFQC Instrument consists of one Quantum Analyzer readout channel, and 6 Signal Generator control channels. Both types of channels consists of several interface units processing analog signals (dark blue color), and several internal units that process digital data (light blue color). The interface units that connect to the front panel are depicted on the left-hand side and the units at the back panel are depicted on the right-hand side of the Figure. Arrows between the panels and the interface units indicate selected physical connections and data flow, whereas double arrows indicate complex-valued information processing. Information indicated in orange is linked to options that can be either ordered at purchase or upgraded later. The ordering guide details the available upgrade options for the SHFQC Qubit Controller and whether the option can be upgraded directly in the field.

shfqc functional diagram
Figure 1. SHFQC instrument functional diagram

Quantum Analyzer Channel

The Quantum Analyzer readout channel has signal generation (Readout Pulse Generator, Oscillator) and signal analysis (Sweeper, Qubit Measurement Unit) functionality, as well as a Monitor Scope. The digital, complex-valued signal from the signal generation is up-converted to microwave frequencies in the analog domain using the Quantum Analyzer Signal Output Module. After passing through the device under test, the analog signal is first down-converted and then digitized in the Quantum Analyzer Signal Input before the complex-valued signal is being analyzed in the Qubit Measurement Unit.

The Quantum Analyzer channel can be configured in two modes:

Qubit Readout

In the Qubit Readout mode, the Readout Pulse Generator outputs the sum of up to 16 individual, user-defined arbitrary waveforms that are stored in separate Waveform Memory blocks, controlled by the Generator Sequencer. In the Qubit Measurement Unit, the signal is then first integrated using up to 16 user-defined, complex-valued Integration Weight Memories. The results of the integration are then discriminated between different qubit states, and the results are forwarded to either the Signal Generator channels or other instruments in real time using either the 32-bit DIO or the ZSync links.

Spectroscopy

In the Spectroscopy mode, the Sweeper controls an Oscillator, hence a single frequency microwave signal is sent to the experiment. The Qubit Measurement Unit then correlates this signal with the original oscillator signal and displays transmission data in the Sweeper module.

Super-high-frequency Signal Inputs

  • Low-noise SHF Inputs, 0.5 - 8.5 GHz frequency range, 1 GHz bandwidth

  • Broadband double super-heterodyne frequency down-conversion

  • Calibrated (Input) Power Range, selectable from -50 dBm to 10 dBm

Super-high-frequency Signal Outputs

  • Low-noise SHF Outputs, 0.5 - 8.5 GHz frequency range, 1 GHz bandwidth

  • Broadband double super-heterodyne frequency up-conversion

  • Calibrated (Output) Power Range, selectable from -30 dBm to 10 dBm

Readout Pulse Generator

  • Arbitrary waveform capability

  • Advanced sequencing

    • looping, branching

    • advanced trigger control (time-staggered readout capability)

  • Up to 16 freely configurable waveform memory blocks of 4 kSa (total 64 kSa)

Qubit Measurement Unit

  • Up to 16 complex integrators with programmable Integration Weight memory (this requires the SHFQC-16W option.)

  • Multistate Discrimination for up to 4 states per qubit

  • Result Logger with real-time averaging and data logging.

Sweeper

  • Controls the numerical Oscillator for fast frequency sweeps in Spectroscopy mode

  • Displays the oscillator-correlated complex-valued data

Monitor Scope

  • Real-time scope to view Input Signals

  • Displays complex signals in time and frequency domain

Signal Generator Channel

Each of the 6 control channels has an arbitrary waveform generator AWG and Modulation functionality. The digital, complex-valued signal from the signal generation is up-converted to microwave frequencies in the analog domain using the Signal Generator Signal Output Module.

Super-high-frequency Signal Outputs

  • Low-noise SHF Outputs, DC - 8.5 GHz frequency range, 1 GHz modulation bandwidth

  • Broadband double super-heterodyne frequency up-conversion

  • Calibrated (Output) Power Range, selectable from -30 dBm to 10 dBm when using the RF path and from -30 dBm to 5 dBm when using the LF path

Advanced Pulse Sequencer

  • Arbitrary Waveform Generator capability

  • Advanced sequencing

    • looping, branching

    • command table

    • advanced trigger control

  • Digital modulation

Shared Resources

The Quantum Analyzer and Signal Generator channels share several functionalities that are used for communication (32-bit DIO, ZSync) and inter-channel synchronization (Hardware Trigger Engine).

Hardware Trigger Engine

  • shared between all channels and modes

  • 2 Marker Outputs and Trigger Inputs of the Quantum Analyzer channel

  • 1 Marker Output and Trigger Input for each Signal Generator channel

High-speed Connectivity

  • SMA connectors on front and back panel for triggers, signals and external clock

  • USB 3.0 high-speed host interface

  • Maintenance USB connection

  • LAN/Ethernet 1 Gbit/s controller interface

  • DIO: 32-bit digital input-output port

  • 2 ZSync connectors for clock synchronization and fast data transfer

  • Clock input/output connectors (10 MHz)

Software Features

  • LabOne Graphic User Interface: Web-based with multi-instrument control

  • Zurich Instruments LabOne Q software for high-level programming of quantum computing experiments.

  • Data server with multi-client support

  • LabOne APIs, including Python, C, LabVIEW, MATLAB, .NET

  • Turnkey software and firmware features for fast system tune-up

Front Panel Tour

The front panel SMA connectors and control LEDs are arranged as shown in Figure 2 and listed in Table 1.

shfqc front panel with letters
Figure 2. SHFQC Qubit Controller 8.5 GHz front panel
Table 1. SHFQC Qubit Controller front panel description
Position Label / Name Description

A

Aux In

analog Auxiliary Input, max. 10 V

B

Out

single-ended waveform Quantum Analyzer Signal Output, 0.5-8.5 GHz, max. 10 dBm

C

Mark

Quantum Analyzer TTL Marker Outputs A and B

D

Trig

Quantum Analyzer TTL Trigger Inputs A and B

E

In

single-ended waveform Quantum Analyzer Signal Input, 0.5-8.5 GHz, max. 10 dBm

F

Trig

Signal Generator TTL Trigger Input

G

Mark

Signal Generator TTL Marker Output

H

Out

single-ended waveform Signal Generator Signal Output, DC-8.5 GHz, max. 10 dBm

I

Aux In

analog Auxiliary Input, max. 10 V

J

multicolor LEDs

off

Instrument off or uninitialized

blink

all LEDs blink for 5 seconds → indicator used by the Identify Device functionality

Busy

unused

Ext Ref

off

External Reference Signal not present/detected

blue

External Reference Signal is present and locked on to

yellow

External Reference Signal present, but not locked on to

red

External Reference Signal present, but lock failed

ZSync

off

no connection

blue
  • steady: ZSync fully connected AND synchronized

  • blinking: ZSync synchronized but not yet fully connected

yellow

ZSync plugged in, but not connected

red

ZSync interface error

Status

off

Instrument off or uninitialized

blue

Instrument is initialized and has no warnings or errors

yellow

Instrument has warnings

red

Instrument has errors

K

on off
Soft power button

Power button with incorporated status LED

off

Instrument off and disconnected from mains power

blue
  • flashing rapidly (>1/sec): Firmware is starting

  • flashing slow (<1/sec): Firmware ready, waiting for connection

  • constant: Instrument ready and active connection over USB or Ethernet

red
  • breathing: Instrument off but connected to mains power → safe to power off using the rear panel switch, or restart using the soft power button

  • flashing: Instrument booting up

  • constant: Fatal error occurred

Back Panel Tour

The back panel is the main interface for power, control, service and connectivity to other ZI instruments. Please refer to Figure 3 and Table 2 for the detailed description of the items.

shfqc back panel with letters
Figure 3. SHFQC Instrument back panel
Table 2. SHFQC Instrument back panel description
Position Label / Name Description

A

safety chassis gnd

Earth ground

4 mm banana jack connector for earth ground, electrically connected to the chassis and the earth pin of the power inlet

B

AC 100 - 240 V

Power inlet, fuse holder, and power switch

C

MDS 1

SMA: bidirectional TTL ports for multi-device synchronization

D

MDS 2

SMA: bidirectional TTL ports for multi-device synchronization

E

Maintenance

Universal Serial Bus (USB) 3.0 port for maintenance and instrument control

F

LAN 1GbE

1 Gbit LAN connector for instrument control

G

DIO 32bit

32-bit digital input/output (DIO) connector

H

USB

Universal Serial Bus (USB) 3.0 port connector → do not use for standard operation

I

ZSync Secondary

Secondary inter-instrument synchronization bus connector

Attention: This is not an Ethernet plug, connection to an Ethernet network might damage the instrument.

J

ZSync Primary

Primary inter-instrument synchronization bus connector

Attention: This is not an Ethernet plug, connection to an Ethernet network might damage the instrument.

K

External Clk In

External Reference Clock Input (10 MHz/100 MHz) for synchronization with other instruments

L

External Clk Out

External Reference Clock Output (10 MHz/100 MHz) for synchronization with other instruments

Ordering Guide

Table 3 provides an overview of the available SHFQC products and option. Upgradeable features are options that can be purchased anytime without the need to send the Instrument back to Zurich Instruments.

Table 3. SHFQC Instrument product codes for ordering
Product code Product name Description Field upgrade possible

SHFQC2

SHFQC Qubit Controller 2-Channel Configuration

Base instrument with 2 SG channels enabled

-

SHFQC4

SHFQC Qubit Controller 4-Channel Configuration

Base instrument with 4 SG channels enabled

-

SHFQC6

SHFQC Qubit Controller 6-Channel Configuration

Base instrument with 6 SG channels enabled

-

SHFQC-2T4

SHFQC2 to SHFQC4 Upgrade Option

Software Upgrades the SHFQC2 to a SHFQC4

yes

SHFQC-2T6

SHFQC2 to SHFQC6 Upgrade Option

Software Upgrades the SHFQC2 to a SHFQC6

yes

SHFQC-4T6

SHFQC4 to SHFQC6 Upgrade Option

Software Upgrades the SHFQC4 to a SHFQC6

yes

SHFQC-16W

SHFQC-16W Integration Weights Extension Option

Option for all SHFQCs

yes

Table 4. Product selector SHFQC
Channel Feature SHFQC2 SHFQC4 SHFQC6 SHFQCX
+ SHFQC-16W

Quantum Analyzer

Readout Channels

1

Number of independent RF readout bands (>1 GHz)

1

Number of integration weights

8

8

8

16

Oscillators

2

Mixer-calibration-free analog frequency conversion
(double super-heterodyne)

yes

Frequency range

0.5-8.5 GHz

Total number of Markers/Triggers

2/2

Vertical resolution Input/Output

14 bit

Sequencing

yes

Signal Generator

Control Channels

2

4

6

X

Number of independent RF control bands (>1 GHz)

1

2

3

see left

Digital oscillators per channel

8

Mixer-calibration-free analog frequency upconversion
(double super-heterodyne)

yes

Frequency range

DC-8.5 GHz

Total number of Markers/Triggers

2/2

4/4

6/6

X/X

Vertical resolution Output

14 bit

Digital IQ modulation

yes

Pulse-level Sequencing

yes

Shared resources

ZSync capability

yes

USB 3.0

yes

LAN 1 Gbit/s

yes